211 pubblicazioni classificate nel seguente modo:

Production of Composite Zinc Oxide–Polylactic Acid Radiopaque Filaments for Fused Deposition Modeling: First Stage of a Feasibility Study
MATERIALS
Autore/i: Cherubini, Francesca; Riberti, Nicole; Schiavone, ANNA MARIA; Davì, Fabrizio; Furlani, Michele; Giuliani, Alessandra; Barucca, Gianni; Cristina Cassani, Maria; Rinaldi, Daniele; Montalto, Luigi
Classificazione: 1 Contributo su Rivista
Abstract: Three-dimensional printing technologies are becoming increasingly attractive for their versatility; the geometrical customizability and manageability of the final product properties are the key points. This work aims to assess the feasibility of producing radiopaque filaments for fused deposition modeling (FDM), a 3D printing technology, starting with zinc oxide (ZnO) and polylactic acid (PLA) as the raw materials. Indeed, ZnO and PLA are promising materials due to their non-toxic and biocompatible nature. Pellets of PLA and ZnO in the form of nanoparticles were mixed together using ethanol; this homogenous mixture was processed by a commercial extruder, optimizing the process parameters for obtaining mechanically stable samples. Scanning electron microscopy analyses were used to assess, in the extruded samples, the homogenous distribution of the ZnO in the PLA matrix. Moreover, X-ray microtomography revealed a certain homogenous radiopacity; this imaging technique also confirmed the correct distribution of the ZnO in the PLA matrix. Thus, our tests showed that mechanically stable radiopaque filaments, ready for FDM systems, were obtained by homogenously loading the PLA with a maximum ZnO content of 6.5% wt. (nominal). This study produced multiple outcomes. We demonstrated the feasibility of producing radiopaque filaments for additive manufacturing using safe materials. Moreover, each phase of the process is cost-effective and green-oriented; in fact, the homogenous mixture of PLA and ZnO requires only a small amount of ethanol, which evaporates in minutes without any temperature adjustment. Finally, both the extruding and the FDM technologies are the most accessible systems for the additive manufacturing commercial apparatuses.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/331752

Inorganic UV filter-based sunscreens labelled as eco-friendly threaten sea urchin populations
ENVIRONMENTAL POLLUTION
Autore/i: Marcellini, F.; Varrella, S.; Ghilardi, M.; Barucca, G.; Giorgetti, A.; Danovaro, R.; Corinaldesi, C.
Classificazione: 1 Contributo su Rivista
Abstract: Although the negative effects of inorganic UV filters have been documented on several marine organisms, sunscreen products containing such filters are available in the market and proposed as eco-friendly substitutes for harmful, and already banned, organic UV filters (e.g. octinoxate and oxybenzone). In the present study, we investigated the effects of four sunscreen products, labelled by cosmetic companies as “eco-friendly”, on the early developmental stages of the sea urchin Paracentrotus lividus, a keystone species occurring in vulnerable coastal habitats. Among sunscreens tested, those containing ZnO and TiO2 or their mix caused severe impacts on sea urchin embryos. We show that inorganic UV filters were incorporated by larvae during their development and, despite the activation of defence strategies (e.g. phagocytosis by coelomocytes), generated anomalies such as skeletal malformations and tissue necrosis. Conversely, the sunscreen product containing only new-generation organic UV filters (e.g. methylene bis-benzotriazolyl tetramethyl, ethylhexyl triazone, butylphenol diethylamino hydroxybenzoyl hexyl benzoate) did not affect sea urchins, thus resulting actually eco-compatible. Our findings expand information on the impact of inorganic UV filters on marine life, corroborate the need to improve the eco-friendliness assessment of sunscreen products and warn of the risk of bioaccumulation and potential biomagnification of inorganic UV filters along the marine food chain.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/329392

Chemical engineering of cationic distribution in spinel ferrite nanoparticles: the effect on the magnetic properties
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autore/i: Baricic, M.; Maltoni, P.; Barucca, G.; Yaacoub, N.; Omelyanchik, A.; Canepa, F.; Mathieu, R.; Peddis, D.
Classificazione: 1 Contributo su Rivista
Abstract: A set of ∼9 nm CoFe2O4 nanoparticles substituted with Zn2+ and Ni2+ was prepared by thermal decomposition of metallic acetylacetonate precursors to correlate the effects of replacement of Co2+ with the resulting magnetic properties. Due to the distinct selectivity of these cations for the spinel ferrite crystal sites, we show that it is possible to tailor the magnetic anisotropy, saturation magnetization, and interparticle interactions of the nanoparticles during the synthesis stage. This approach unlocks new possibilities for enhancing the performance of spinel ferrite nanoparticles in specific applications. Particularly, our study shows that the replacement of Co2+ by 48% of Zn2+ ions led to an increase in saturation magnetization of approximately 40% from ∼103 A m2 kg−1 to ∼143 A m2 kg−1, whereas the addition of Ni2+ at a similar percentage led to an ∼30% decrease in saturation magnetization to 68-72 A m2 kg−1. The results of calculations based on the two-sublattice Néel model of magnetization match the experimental findings, demonstrating the model's effectiveness in the strategic design of spinel ferrite nanoparticles with targeted magnetic properties through doping/inversion degree engineering.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326837

Unraveling Exchange Coupling in Ferrites Nano-Heterostructures
SMALL
Autore/i: Maltoni, P.; Barucca, G.; Rutkowski, B.; Spadaro, M. C.; Jonsson, P. E.; Varvaro, G.; Yaacoub, N.; De Toro, J. A.; Peddis, D.; Mathieu, R.
Classificazione: 1 Contributo su Rivista
Abstract: The magnetic coupling of a set of SrFe12O19/CoFe2O4 nanocomposites is investigated. Advanced electron microscopy evidences the structural coherence and texture at the interfaces of the nanostructures. The fraction of the lower anisotropy phase (CoFe2O4) is tuned to assess the limits that define magnetically exchange-coupled interfaces by performing magnetic remanence, first-order reversal curves (FORCs), and relaxation measurements. By combining these magnetometry techniques and the structural and morphological information from X-ray diffraction, electron microscopy, and Mössbauer spectrometry, the exchange intergranular interaction is evidenced, and the critical thickness within which coupled interfaces have a uniform reversal unraveled.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/325993

Co/Pd-based spin-valves with perpendicular magnetic anisotropy on flexible substrates. Direct deposition vs transfer-and-bonding approaches
APPLIED SURFACE SCIENCE
Autore/i: Hassan, M.; Laureti, S.; Rinaldi, C.; Fagiani, F.; Barucca, G.; Gerardino, A.; Schmidt, N.; Fix, M.; Albrecht, M.; Varvaro, G.
Classificazione: 1 Contributo su Rivista
Abstract: Flexible spintronics is an emerging field of research that has received increasing attention due to the additional functionalities that are allowed (lightweight, flexibility, shape-ability, wearability) with respect to conventional rigid systems. In this work, different strategies for the fabrication of flexible spintronic devices with perpendicular magnetic anisotropy are compared, i.e., transfer-and-bonding approaches exploiting wet and dry lift-off methods, and direct deposition on flexible substrates. To evaluate the potential of the proposed strategies, Co/Pd-based giant magneto-resistive spin-valves including a synthetic antiferromagnet reference electrode were investigated. Such stacks represent a demanding model system, owing to the large number of interfaces whose quality strongly affects the overall magnetic and electric performances. The advantages and drawbacks of the different strategies are discussed to provide crucial indications for the development of flexible spintronic devices of any complexity. Based on the results, the most suitable option for achieving high-quality heterostructures on large area surfaces via direct deposition is using polyethylene naphthalate (Teonex®) tapes, provided that the processing and operating temperatures are relatively low (<525 K). On the other hand, if the process requires higher temperatures, the dry lift-off method exploiting the low adhesion between an Au underlayer and the SiOx/Si(100) substrate is the preferred alternative.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/321677

Atmospheric Pressure Plasma Deposition of Hybrid Nanocomposite Coatings Containing TiO2 and Carbon-Based Nanomaterials
MOLECULES
Autore/i: Del Sole, R.; Lo Porto, C.; Lotito, S.; Ingrosso, C.; Comparelli, R.; Curri, M. L.; Barucca, G.; Fracassi, F.; Palumbo, F.; Milella, A.
Classificazione: 1 Contributo su Rivista
Abstract: Among the different applications of TiO2, its use for the photocatalytic abatement of organic pollutants has been demonstrated particularly relevant. However, the wide band gap (3.2 eV), which requires UV irradiation for activation, and the fast electron-hole recombination rate of this n-type semiconductor limit its photocatalytic performance. A strategy to overcome these limitations relies on the realization of a nanocomposite that combines TiO2 nanoparticles with carbon-based nanomaterials, such as rGO (reduced graphene oxide) and fullerene (C60). On the other hand, the design and realization of coatings formed of such TiO2-based nanocomposite coatings are essential to make them suitable for their technological applications, including those in the environmental field. In this work, aerosol-assisted atmospheric pressure plasma deposition of nanocomposite coatings containing both TiO2 nanoparticles and carbon-based nanomaterials, as rGO or C60, in a siloxane matrix is reported. The chemical composition and morphology of the deposited films were investigated for the different types of prepared nanocomposites by means of FT-IR, FEG-SEM, and TEM analyses. The photocatalytic activity of the nanocomposite coatings was evaluated through monitoring the photodegradation of methylene blue (MB) as a model organic pollutant. Results demonstrate that the nanocomposite coatings embedding rGO or C60 show enhanced photocatalytic performance with respect to the TiO2 counterpart. In particular, TiO2/C60 nanocomposites allow to achieve 85% MB degradation upon 180 min of UV irradiation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/321675

Morpho-Structural and Magnetic Properties of CoFe2O4/SiO2 Nanocomposites: The Effect of the Molecular Coating
JOURNAL OF PHYSICAL CHEMISTRY. C
Autore/i: Slimani, S.; Talone, A.; Abdolrahimi, M.; Imperatori, P.; Barucca, G.; Fiorani, D.; Peddis, D.
Classificazione: 1 Contributo su Rivista
Abstract: The use of magnetic nanoarchitecture in several applications is often limited by the lack of noninteracting particles, due to the frequent presence of clusters and aggregates of particles. Here, we report an investigation of the interparticle interactions by changing the molecular coating on ∼5 nm CoFe2O4 nanoparticles embedded in a silica structure. The magnetic investigation at a low temperature allows revealing the key role of organic ligands in tuning the morpho-structural properties of hybrid materials. Cobalt ferrite-coated nanoparticles were prepared by the polyol method using triethylene glycol as a co-reagent (CFOT) and by the exchange ligand process using dihydroxyhydrocinnamic acid (CFOH). Then, magnetic mesoporous silica nanocomposites have been prepared starting from CFOT (CFOTS) and CFOH (CFOHS). For the CFOTS sample, the interparticle distance did not change after coating, whereas the CFOHS sample showed an increase in the interparticle distance by 23%. This value has been obtained by investigating interparticle interactions by remanence techniques, which represent a good approach to determine the approximated values of interparticle distances in complex systems. The measurements showed that the silica coating produces a reduction of 47% in the dipolar interaction strength for the CFOHS sample, whereas no significant change was observed for the CFOTS sample. The differences in magnetic response upon varying the molecular coating of nanoparticles are due to the different interactions of the molecular ligands with silica, resulting in a change of interparticle distances and then magnetic interactions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/321674

Synthetic antiferromagnets for biomedical and flexible spintronic applications
2023 IEEE Nanotechnology Materials and Devices Conference, NMDC 2023
Autore/i: Hassan, M.; Laureti, S.; Peddis, D.; Gerardino, A. M.; Barucca, G.; Fagiani, F.; Rinaldi, C.; Makushko, P.; Makarov, D.; Schmidt, N.; Albrecht, M.; Varvaro, G.
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Synthetic antiferromagnets (SAFs) have received a renewed attention in the last few years as they exhibit key features of crystal antiferromagnets (e.g., zero remanence, high robustness against external fields) while offering additional advantages, such as easy manipulation and control of magnetic configuration, and high tunability of magnetic properties. The peculiar properties of SAF are here exploited to develop magnetic microdisks with perpendicular magnetic anisotropy for biomedical applications and flexible GMR spin-valves with potential interest in many technological fields including wearable devices, soft robotics, and bio-integrated electronics.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326273

Study on the mechanical properties of magnetron sputtered W-based degradable radiopaque coatings for tiny biodegradable metallic endovascular implants
EUROPEAN JOURNAL OF MECHANICS. A, SOLIDS
Autore/i: Ravanbakhsh, S.; Paternoster, C.; Chevallier, P.; Barucca, G.; Mengucci, P.; Parapari, S. S.; Shekargoftar, M.; Cabibbo, M.; Sturm, S.; Sarkissian, A.; Fortin, M. -A.; Mantovani, D.
Classificazione: 1 Contributo su Rivista
Abstract: Bioresorbable metals constitutes a new class of biomaterials, and raised increasing interest over the last decade to fabricate tiny endovascular metallic implants. However, the lack of visibility especially when tiny bioresorbable implants are implanted is a major concern in clinics, affecting their implantation and limiting their clinical follow-up. Among the radiopaque elements, tungsten (W) is a promising candidate to be used as a radiopaque resorbable agent due to its high radiopacity and high corrosion rate. Therefore, this research aimed to produce a W-based radiopaque coatings providing mechanical properties close to Fe–Mn–C alloys. The mechanical mismatch between the substrate and the coating was also investigated and optimized. A magnetron sputtering was used to deposit Fe–Mn–C–W coatings (A and B) with 38 and 79 at. % of W, respectively, and at different deposition temperatures, i.e. 25, 300 and 600 °C. TEM and XRD analyses evidenced that coatings A, ∼38 at.% of W, at all deposition temperature, exhibited an amorphous structure. The amorphous structure of coating A was composed of a matrix of Fe with tiny α-W nanocrystals embedded, while coating B (W: 73–79 at. %) displayed the presence of a pyramidal-like β-W phase, observed only at low deposition temperature (25 °C). The presence of this β-W phase significantly increased the coating roughness, and increased its corrosion rate. Mechanical properties, assessed by nanoindentation tests, confirmed that samples containing β-W exhibited higher elastic modulus and hardness when compared to other samples. X-ray studies by CT scanning demonstrated that 1 μm of coatings A and B deposited at high temperature could increase significantly the radiopacity of the samples by 109% and 62%, respectively. On the basis of all these results, the coating A deposited at 600 °C appears to be the most promising coating for X-ray enhancement as well as providing the mechanical properties matching those of Fe–Mn alloy.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/321676

Tunable particle-agglomeration and magnetic coupling in bi-magnetic nanocomposites
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autore/i: Maltoni, P.; Baricic, M.; Barucca, G.; Spadaro, M. C.; Arbiol, J.; Yaacoub, N.; Peddis, D.; Mathieu, R.
Classificazione: 1 Contributo su Rivista
Abstract: A set of non-stoichiometric Zn-Co-ferrite nanoparticles (NPs) was prepared by thermal decomposition of metallic complexes, in the presence of oleic acid, and, after a ligand-exchange process, was coated by a hydrophilic surfactant: these NPs were used as seeds in a sol-gel self-combustion synthesis to prepare nanocomposites (NCs) with a fixed weight ratio. Our focus here is the development of an efficient synthetic approach to control the magnetic coupling between a hard-magnetic matrix (Sr-ferrite) and NPs. The physico-chemical synthetic conditions (temperature, pH, colloidal stability) were optimized in order to tune their effect on the final particles’ agglomeration in the matrix. We demonstrate that our synthetic approach is a novel way to produce strongly magnetically coupled NCs, where the final extrinsic properties could be tuned by controlling (i) the agglomeration of seeds in the matrix and (ii) their elemental doping.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326272

Nanostructured iron oxide thin films deposited by RF sputtering as catalysts for the heterogeneous solar photo-Fenton reaction
VACUUM
Autore/i: Bosso, P.; Del Sole, R.; Milella, A.; Mengucci, P.; Barucca, G.; Armenise, V.; Bianco, G. V.; Fracassi, F.; Palumbo, F.
Classificazione: 1 Contributo su Rivista
Abstract: Nanostructured iron oxide coatings have been deposited by plasma sputtering by different approaches, with and without thermal annealing, with the aim of preparing supported catalysts for solar photo-Fenton. Depending on the experimental conditions explored (O2 content in the feed, annealing or bilayer approach) the phase composition of iron oxide changes and the surface nanostructure as well. The evaluation of methylene blue degradation in photo-Fenton reaction indicates a good performance of the investigated materials. Degradation percentage between 84 and 97% have been obtained in 180 min with a constant reaction rate as high as 18.0 × 10−3 min−1, with the best result for a bilayer sample obtained without thermal annealing. This preliminary investigation highlights that the photoactivity of the coatings is related not only to the content of α-Fe2O3, but also to the presence of developed nanostructures on the coating surface, making the material more active. The proposed method for producing supported catalyst based on photo-Fenton reaction is straightforward, and the possibility to reuse the catalyst up to ten reaction cycles is demonstrated.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/312232

Transformation of industrial and organic waste into titanium doped activated carbon – cellulose nanocomposite for rapid removal of organic pollutants
JOURNAL OF HAZARDOUS MATERIALS
Autore/i: Maqbool, Qaisar; Barucca, Gianni; Sabbatini, Simona; Parlapiano, Marco; Ruello, Maria Letizia; Tittarelli, Francesca
Classificazione: 1 Contributo su Rivista
Abstract: Production of cost-efficient composite materials with desired physicochemical properties from low-cost waste material is much needed to meet the growing needs of the industrial sector. As a step forward, the current study reports for the first time an effective utilization of industrial metal (inorganic) waste as well as fall leaves (organic waste), to produce three types of nanomaterials at the same time; “Titanium Doped Activated Carbon Nanostructures (Ti-ACNs)”, “Nanocellulose (NCel)”, and combination of both “Titanium Doped Activated Carbon Cellulose Nanocomposite (Ti-AC-Cel-NC)”. X-ray diffraction (XRD), transmission electron microscopy (TEM) and microanalysis (EDXS) measurements reveal that the Ti-ACNs material is formed by Ti-nanostructures, generally poorly crystalized but in some cases forming hexagonal Ti-crystallites of 15 nm, embedded in mutated graphene clouds. Micro- Fourier transform infrared spectroscopy (micro-FTIR) confirms that the chemical structure of NCel with bond vibrations between 1035 to 2917 cm 1 remained preserved during Ti-AC-Cel-NC formation. The prepared materials (Ti-ACNs, Ti-AC-Cel-NC) have demonstrated rapid removal of organic pollutants (Crystal Violet, Methyl Violet) from wastewater through surface adsorption and photocatalysis. In the first 20 min, Ti-ACNs have adsorbed ≈87% of the organic pollutants and further photocatalyzed them up to ≈96%. When Ti-ACNs are combined with NCel, their efficiency is increased of about four times. This performance originates from the adsorption by mutated graphene-like carbon and assisted photocatalysis by Ti nanostructures as well as the good supporting capacity of NCel for the homogenous Ti-ACNs distribution.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/291730

Development of Ti-Mo-Fe alloys combining different plastic deformation mechanisms for improved strength-ductility trade-off and high work hardening rate
JOURNAL OF ALLOYS AND COMPOUNDS
Autore/i: Catanio Bortolan, C.; Contri Campanelli, L.; Mengucci, P.; Barucca, G.; Giguere, N.; Brodusch, N.; Paternoster, C.; Bolfarini, C.; Gauvin, R.; Mantovani, D.
Classificazione: 1 Contributo su Rivista
Abstract: Titanium-based biomaterials are the gold standard for orthopedic implants; however, they are not generally suitable for the manufacture of intravascular stents. Their low strength-ductility trade-off and low work hardening rate are their main limitations. However, Ni-free alloys are desirable for such application in order to avoid allergic reactions caused by the high Ni-content materials currently applied. Therefore, in this study, three alloys of the Ti-Mo-Fe system (Ti-8Mo-2Fe, Ti-9Mo-1Fe and Ti-10.5Mo-1Fe) were designed to present high strength-ductility compromise and high work hardening rate. Their microstructures, mechanical properties and plastic deformation mechanism were investigated. Athermal ω precipitates were observed in the β matrix of all solution-treated alloys. In the solution-treated β matrix of the Ti-9Mo-1Fe alloy, additional nanometer-sized α" particles were detected by transmission electron microscopy (TEM). Although the combined TWIP/TRIP effects were expected by the design method on the Ti-8Mo-2Fe and Ti-9Mo-1Fe alloys, no TRIP effect was actually observed. In fact, stress-induced martensitic (SIM) transformation occurred mainly at the {332}<113> twins/matrix interfaces for all the strained microstructures and acted as a localized stress-relaxation mechanism, delaying the fracture. Based on the electron backscatter diffraction (EBSD) analyses, in the Ti-8Mo-2Fe and Ti-10.5Mo-1Fe alloys, the formation of a dense network of {332}<113> twins was responsible for their high and steady work hardening rates (1370 and 1120 MPa) and large uniform elongations (22% and 34%). The absence of SIM α" as the primary mechanism of plastic deformation and solid solution hardening of Fe resulted in their high strengths (yield strength of 772 and 523 MPa). In Ti-9Mo-1Fe, the formation of mechanical twinning was hindered, resulting in limited strain-hardening capability and low uniform elongation (6%). The nanometer-sized α" particles in its β matrix along with the athermal ω precipitates are thought to impair the mechanical twinning and the ductility of this alloy.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306721

Temperature Dependence of Electrical Resistance in Graphite Films Deposited on Glass and Low-Density Polyethylene by Spray Technology
COATINGS
Autore/i: Longo, A.; Di Bartolomeo, A.; Faella, E.; Pelella, A.; Giubileo, F.; Sorrentino, A.; Palomba, M.; Carotenuto, G.; Barucca, G.; Tagliaferro, A.; Coscia, U.
Classificazione: 1 Contributo su Rivista
Abstract: Graphite lacquer was simply sprayed on glass and low-density polyethylene (LDPE) substrates to obtain large area films. Scanning Electron Microscopy (SEM) images, Raman spectra, X Ray Diffraction (XRD) spectra and current-voltage characteristics show that at room temperature, the as-deposited films on different substrates have similar morphological, structural and electrical properties. The morphological characterization reveals that the films are made of overlapped graphite platelets (GP), each composed of nanoplatelets with average sizes of a few tens of nanometers and about forty graphene layers. The thermoresistive properties of the GP films deposited on the different substrates and investigated in the temperature range from 20 to 120 °C show very different behaviors. For glass substrate, the resistance of the film decreases monotonically as a function of temperature by 7%; for LDPE substrate, the film resistance firstly increases more than one order of magnitude in the 20–100 °C range, then suddenly decreases to a temperature between 105 and 115 °C. These trends are related to the thermal expansion properties of the substrates and, for LDPE, also to the phase transitions occurring in the investigated temperature range, as evidenced by differential scanning calorimetry measurements.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/312231

Silk fibroin films with embedded magnetic nanoparticles: evaluation of the magneto-mechanical stimulation effect on osteogenic differentiation of stem cells
NANOSCALE
Autore/i: Del Bianco, L.; Spizzo, F.; Yang, Y.; Greco, G.; Gatto, M. L.; Barucca, G.; Pugno, N. M.; Motta, A.
Classificazione: 1 Contributo su Rivista
Abstract: We report about a biomaterial in the form of film ∼10 μm thick, consisting of a silk fibroin matrix with embedded iron oxide superparamagnetic nanoparticles, for prospective applications as bioactive coating in regenerative medicine. Films with different load of magnetic nanoparticles are produced (nanoparticles/silk fibroin nominal ratio = 5, 0.5 and 0 wt%) and the structural, mechanical and magnetic properties are studied. The nanoparticles form aggregates in the silk fibroin matrix and the film stiffness, as tested by nanoindentation, is spatially inhomogeneous, but the protein structure is not altered. In vitro biological tests are carried out on human bone marrow-derived mesenchymal stem cells cultured on the films up to 21 days, with and without an applied static uniform magnetic field. The sample with the highest nanoparticles/silk fibroin ratio shows the best performance in terms of cell proliferation and adhesion. Moreover, it promotes a faster and better osteogenic differentiation, particularly under magnetic field, as indicated by the gene expression level of typical osteogenic markers. These findings are explained in light of the results of the physical characterization, combined with numerical calculations. It is established that the applied magnetic field triggers a virtuous magneto-mechanical mechanism in which dipolar magnetic forces between the nanoparticle aggregates give rise to a spatial distribution of mechanical stresses in the silk fibroin matrix. The film with the largest nanoparticle load, under cell culture conditions (i.e. in aqueous environment), undergoes matrix deformations large enough to be sensed by the seeded cells as mechanical stimuli favoring the osteogenic differentiation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/307441

Disclosing the Nature of Asymmetric Interface Magnetism in Co/Pt Multilayers
ACS APPLIED MATERIALS & INTERFACES
Autore/i: Verna, A.; Alippi, P.; Offi, F.; Barucca, G.; Varvaro, G.; Agostinelli, E.; Albrecht, M.; Rutkowski, B.; Ruocco, A.; Paoloni, D.; Valvidares, M.; Laureti, S.
Classificazione: 1 Contributo su Rivista
Abstract: Nowadays, a wide number of applications based on magnetic materials rely on the properties arising at the interface between different layers in complex heterostructures engineered at the nanoscale. In ferromagnetic/heavy metal multilayers, such as the [Co/Pt]N and [Co/Pd]N systems, the magnetic proximity effect was demonstrated to be asymmetric, thus inducing a magnetic moment on the Pt (Pd) layer that is typically higher at the top Co/Pt(Pd) interface. In this work, advanced spectroscopic and imaging techniques were combined with theoretical approaches to clarify the origin of this asymmetry both in Co/Pt trilayers and, for the first time, in multilayer systems that are more relevant for practical applications. The different magnetic moment induced at the Co/Pt interfaces was correlated to the microstructural features that are in turn affected by the growth processes that induce a different intermixing during the film deposition, thus influencing the interface magnetic profile.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306723

Improving the radiopacity of Fe–Mn biodegradable metals by magnetron-sputtered W–Fe–Mn–C coatings: Application for thinner stents
BIOACTIVE MATERIALS
Autore/i: Ravanbakhsh, S.; Paternoster, C.; Barucca, G.; Mengucci, P.; Gambaro, S.; Lescot, T.; Chevallier, P.; Fortin, M. -A.; Mantovani, D.
Classificazione: 1 Contributo su Rivista
Abstract: In this exploratory work, micrometric radiopaque W–Fe–Mn–C coatings were produced by magnetron sputtering plasma deposition, for the first time, with the aim to make very thin Fe–Mn stents trackable by fluoroscopy. The power of Fe–13Mn-1.2C target was kept constant at 400 W while that of W target varied from 100 to 400 W producing three different coatings referred to as P100, P200, P400. The effect of the increased W power on coatings thickness, roughness, structure, corrosion behavior and radiopacity was investigated. The coatings showed a power-dependent thickness and W concentration, different roughness values while a similar and uniform columnar structure. An amorphous phase was detected for both P100 and P200 coatings while γ-Fe, bcc-W and W3C phases found for P400. Moreover, P200 and P400 showed a significantly higher corrosion rate (CR) compared to P100. The presence of W, W3C as well as the Fe amount variation determined two different micro-galvanic corrosion mechanisms significantly changing the CR of coatings, 0.26 ± 0.02, 59.68 ± 1.21 and 59.06 ± 1.16 μm/year for P100, P200 and P400, respectively. Sample P200 with its most uniform morphology, lowest roughness (RMS = 3.9 ± 0.4 nm) and good radiopacity (∼6%) appeared the most suitable radiopaque biodegradable coating investigated in this study.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/295106

Extraction efficiency of different microplastic polymers from deep-sea sediments and their quantitative relevance
FRONTIERS IN MARINE SCIENCE
Autore/i: Canensi, S.; Barucca, G.; Corinaldesi, C.
Classificazione: 1 Contributo su Rivista
Abstract: An increasing number of methods for extracting microplastic particles from marine sediments have been published but without evaluating the extraction efficiency. Furthermore, while most of the procedures developed have been applied to sandy sediments from shallow water habitats, specific and standardized procedures for deep-water sediments (> 200 meters deep) are limited. In this study, we describe a specific protocol for extracting microplastics (2- 1000 µm) from deep-sea sediments and for quantifying and identifying them. We also assessed its extraction efficiency, which resulted in a high recovery (on average ca. 60%, and up to 80%) particularly, for polyethylene, polypropylene, and polystyrene. This method can be applied to all fine-grained/muddy sediments and allows the extraction of even the smallest fraction of microplastics (<20 µm), which are expected to have the most severe effects on marine biodiversity and ecosystem functioning and ultimately also have implications for human health.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/312230

Thin-Film Heterostructures Based on Co/Ni Synthetic Antiferromagnets on Polymer Tapes: Toward Sustainable Flexible Spintronics
ACS APPLIED MATERIALS & INTERFACES
Autore/i: Hassan, M.; Laureti, S.; Rinaldi, C.; Fagiani, F.; Barucca, G.; Casoli, F.; Mezzi, A.; Bolli, E.; Kaciulis, S.; Fix, M.; Ullrich, A.; Albrecht, M.; Varvaro, G.
Classificazione: 1 Contributo su Rivista
Abstract: Synthetic antiferromagnets with perpendicular magnetic anisotropy (PMA-SAFs) have gained growing attention for both conventional and next-generation spin-based technologies. While the progress of PMA-SAF spintronic devices on rigid substrates has been remarkable, only few examples of flexible thin-film heterostructures are reported in the literature, all containing platinum group metals (PGMs). Systems based on Co/Ni may offer additional advantages with respect to devices containing PGMs, i.e., low damping and high spin polarization. Moreover, limiting the use of PGMs may relieve the demand for critical raw materials and reduce the environmental impact of related technologies, thus contributing to the transition toward a more sustainable future. Here, we discuss for the first time the realization of Co/Ni-based PMA-SAFs on polymer tapes and exploit it to obtain flexible giant magneto-resistive spin valves (GMR-SVs) with perpendicular magnetic anisotropy. Several combinations of buffer and capping layers (i.e., Pt, Pd, and Cu/Ta) are also investigated. High-quality flexible SAFs with a fully compensated antiferromagnetic region and SVs with a sizable GMR ratio (up to 4.4%), in line with the values reported in the literature for similar systems on rigid substrates, were obtained in all cases. However, we demonstrate that PGMs allows achieving the best results when used as a buffer layer, while Cu is the best choice as a capping layer to optimize the properties of the stacks. We justify the role of buffer and capping layers in terms of different interdiffusion mechanisms occurring at the interface between the metallic layers. These results, along with the high robustness of the samples' properties against bending (up to 180°), indicate that complex and bendable Co/Ni-based heterostructures with reduced content of PGMs can be obtained on flexible tapes, allowing for the development of novel flexible and sustainable spintronic devices for applications in many fields including wearable electronics, soft robotics, and biomedicine.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/312229

Microwave driven synthesis of narrow bandgap alpha-tin nanoparticles on silicon
MATERIALS & DESIGN
Autore/i: Mazzetta, I.; Viti, L.; Rigoni, F.; Quaranta, S.; Gasparotto, A.; Barucca, G.; Palma, F.; Riello, P.; Cattaruzza, E.; Asgari, M.; Vitiello, M.; Irrera, F.
Classificazione: 1 Contributo su Rivista
Abstract: This work proposes a microwave-based synthetic route for the preparation of tin nanospheres with a diamond-like α-phase structure on silicon. The main characteristics of the synthesized material are an extraordinarily narrow (around 50 meV) direct bandgap and an improved thermal stability (up to 200° C). Structural and compositional characterizations showed a core–shell structure comprised of an outer amorphous oxide shell and inner core containing α-phase tin domains. Microwaves turned out to be instrumental in achieving the specific nanostructures reported, due to their peculiar heating characteristics. Low pressure, low temperature and compatibility with integrated circuits manufacturing represent the most innovative features of the present synthetic process.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306722

Towards bi-magnetic nanocomposites as permanent magnets through the optimization of the synthesis and magnetic properties of SrFe12O19 nanocrystallites
JOURNAL OF PHYSICS D. APPLIED PHYSICS
Autore/i: Maltoni, P.; Sarkar, T.; Varvaro, G.; Barucca, G.; Ivanov, S. A.; Peddis, D.; Mathieu, R.
Classificazione: 1 Contributo su Rivista
Abstract: Sol-gel synthesis was used in order to obtain nanocrystallites of the SrFe12O19 (SFO) hexaferrite in an efficient and reliable way. By optimizing the initial synthetic conditions, we were able to control the size of the nanoparticles (NPs), at lower annealing temperature. The x-ray powder diffraction, transmission electron microscopy (TEM), and magnetic measurements have demonstrated a significant relation between the morphology, size, and magnetic properties of the nanoscale SFO, revealing a definite dependence on the crystallite size along the c-axis. The obtained NPs appear almost isotropic, in the form of platelets and exhibit similar magnetic performance, in terms of the energy product (BH)MAX, thus, demonstrating the suitability of reducing the annealing temperature without any deterioration in the magnetic properties. Additionally, this work illustrates the feasibility of the sol-gel bottom-up approach to employ magnetic NPs as building-blocks for designing hard/soft exchange-coupled bi-magnetic nanocomposites, combining the high coercivity of a hard phase (SFO) and the high saturation magnetization of a soft phase (CoFe2O4); in this regard, we discuss the tunability of the magnetic anisotropy by symbiotically restricting the growth of both phases.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/288860

PANDA Phase one
EUROPEAN PHYSICAL JOURNAL. A, HADRONS AND NUCLEI
Autore/i: Barucca, G.; Davi', F.; Lancioni, G.; Mengucci, P.; Montalto, L.; Natali, P. P.; Paone, N.; Rinaldi, D.; Scalise, L.; Krusche, B.; Steinacher, M.; Liu, Z.; Liu, C.; Liu, B.; Shen, X.; Sun, S.; Zhao, G.; Zhao, J.; Albrecht, M.; Alkakhi, W.; Bökelmann, S.; Coen, S.; Feldbauer, F.; Fink, M.; Frech, J.; Freudenreich, V.; Fritsch, M.; Grochowski, J.; Hagdorn, R.; Heinsius, F. H.; Held, T.; Holtmann, T.; Keshk, I.; Koch, H.; Kopf, B.; Kümmel, M.; Ner, M. Kü.; Li, J.; Linzen, L.; Maldaner, S.; Oppotsch, J.; Pankonin, S.; Pelizäus, M.; Pflüger, S.; Reher, J.; Reicherz, G.; Schnier, C.; Steinke, M.; Triffterer, T.; Wenzel, C.; Wiedner, U.; Denizli, H.; Er, N.; Keskin, U.; Yerlikaya, S.; Yilmaz, A.; Beck, R.; Chauhan, V.; Hammann, C.; Hartmann, J.; Ketzer, B.; Müllers, J.; Salisbury, B.; Schmidt, C.; Thoma, U.; Urban, M.; Bianconi, A.; Bragadireanu, M.; Pantea, D.; Rimjaem, S.; Domagala, M.; Filo, G.; Lisowski, E.; Lisowski, F.; Michałek, M.; Pozna´ nski, P.; Płazek, J.; Korcyl, K.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Firlej, M.; Fiutowski, T.; Idzik, M.; Moron, J.; Swientek, K.; Terlecki, P.; Korcyl, G.; Lalik, R.; Malige, A.; Moskal, P.; Nowakowski, K.; Przygoda, W.; Rathod, N.; Salabura, P.; Smyrski, J.; Augustin, I.; Böhm, R.; Lehmann, I.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Flemming, H.; Gerhardt, A.; Götzen, K.; Heinz, A.; Jiang, P.; Karabowicz, R.; Koch, S.; Kurilla, U.; Lehmann, D.; Lühning, J.; Lynen, U.; Orth, H.; Peters, K.; Pütz, J.; Ritman, J.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Voss, B.; Wieczorek, P.; Abazov, V.; Alexeev, G.; Barabanov, M. Yu.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Galoyan, A.; Golovanov, G.; Koshurnikov, E. K.; Lobanov, Y. Yu.; Olshevskiy, A. G.; Piskun, A. A.; Samartsev, A.; Shimanski, S.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Tokmenin, V.; Uzhinsky, V.; Verkheev, A.; Vodopianov, A.; Zhuravlev, N. I.; Watts, D.; Böhm, M.; Eyrich, W.; Lehmann, A.; Miehling, D.; Pfaffinger, M.; Seth, K.; Xiao, T.; Ali, A.; Hamdi, A.; Himmelreich, M.; Krebs, M.; Nakhoul, S.; Nerling, F.; Gianotti, P.; Lucherini, V.; Bracco, G.; Bodenschatz, S.; Brinkmann, K. T.; Brück, L.; Diehl, S.; Dormenev, V.; Düren, M.; Erlen, T.; Hahn, C.; Hayrapetyan, A.; Hofmann, J.; Kegel, S.; Khalid, F.; Köseoglu, I.; Kripko, A.; Kühn, W.; Metag, V.; Moritz, M.; Nanova, M.; Novotny, R.; Orsich, P.; Pereira-de-Lira, J.; Sachs, M.; Schmidt, M.; Schubert, R.; Strickert, M.; Wasem, T.; Zaunick, H. G.; Tomasi-Gustafsson, E.; Glazier, D.; Ireland, D.; Seitz, B.; Kappert, R.; Kavatsyuk, M.; Loehner, H.; Messchendorp, J.; A, ; Rodin, V.; Kalita, K.; Huang, G.; Liu, D.; Peng, H.; Qi, H.; Sun, Y.; Zhou, X.; Kunze, M.; Azizi, K.; Olgun, A. T.; Tavukoglu, Z.; Derichs, A.; Dosdall, R.; Esmail, W.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Jokhovets, L.; Kannika, J.; Kulessa, P.; Orfanitski, S.; Perez-Andrade, G.; Prasuhn, D.; Prencipe, E.; Rosenthal, E.; Schadmand, S.; Schmitz, R.; Scholl, A.; Sefzick, T.; Serdyuk, V.; Stockmanns, T.; Veretennikov, D.; Wintz, P.; Wüstner, P.; Xu, H.; Zhou, Y.; Cao, X.; Hu, Q.; Liang, Y.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Lauth, W.; Leithoff, H. H.; Merkel, H.; Müller, U.; Petersen, J.; Pochodzalla, J.; Schlimme, S.; Sfienti, C.; Thiel, M.; Bleser, S.; Bölting, M.; Capozza, L.; Dbeyssi, A.; Ehret, A.; Klasen, R.; Kliemt, R.; Maas, F.; Motzko, C.; Noll, O.; Rodríguez Piñeiro, D.; Schupp, F.; Steinen, M.; Wolff, S.; Zimmermann, I.; Kazlou, D.; Korzhik, M.; Missevitch, O.; Balanutsa, P.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Golubev, A.; Kantsyrev, A.; Kirin, D. Y.; Kristi, N.; Ladygina, E.; Luschevskaya, E.; Matveev, V. A.; Panjushkin, V.; Stavinskiy, A. V.; Balashoff, A.; Boukharov, A.; Bukharova, M.; Malyshev, O.; Vishnevsky, E.; Bonaventura, D.; Brand, P.; Hetz, B.; Hüsken, N.; Kellers, J.; Khoukaz, A.; Klostermann, D.; Mannweiler, C.; Vestrick, S.; Bumrungkoh, D.; Herold, C.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Manasatitpong, K.; Nasawad, T.; Pongampai, S.; Simantathammakul, T.; Srisawad, P.; Wongprachanukul, N.; Yan, Y.; Yu, C.; Zhang, X.; Zhu, W.; Antokhin, E.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, V. E.; Kuyanov, I. A.; Pivovarov, S.; Pyata, E.; Tikhonov, Y.; Blinov, A. E.; Kononov, S.; Kravchenko, E. A.; Lattery, M.; Boca, G.; Duda, D.; Finger, M.; Finger Jr., M.; Kveton, A.; Prochazka, I.; Slunecka, M.; Volf, M.; Jary, V.; Korchak, O.; Marcisovsky, M.; Neue, G.; Novy, J.; Tomasek, L.; Tomasek, M.; Virius, M.; Vrba, V.; Abramov, V.; Bukreeva, S.; Chernichenko, S.; Derevschikov, A.; Ferapontov, V.; Goncharenko, Y.; Levin, A.; Maslova, E.; Melnik, Y.; Meschanin, A.; Minaev, N.; Mochalov, V.; Moiseev, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Belostotski, S.; Fedotov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Cederwall, B.; Preston, M.; Tegner, P. E.; Wölbing, D.; Gandhi, K.; Rai, A. K.; Godre, S.; Crede, V.; Dobbs, S.; Eugenio, P.; Bussa, M. P.; Spataro, S.; Calvo, D.; De Remigis, P.; Filippi, A.; Mazza, G.; Wheadon, R.; Iazzi, F.; Lavagno, A.; Akram, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Regina, J.; Rieger, J.; Schönning, K.; Wolke, M.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Tarasiuk, J.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Amsler, C.; Bühler, P.; Marton, J.; Zimmermann, S.; Fischer, C. S.; Haidenbauer, J.; Hanhart, C.; Lutz, M. F. M.; Ryan, Sinéad M.
Classificazione: 1 Contributo su Rivista
Abstract: The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or PANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the nonperturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/290677

Flexible Magnetoreceptor with Tunable Intrinsic Logic for On-Skin Touchless Human-Machine Interfaces
ADVANCED FUNCTIONAL MATERIALS
Autore/i: Makushko, P.; Oliveros Mata, E. S.; Canon Bermudez, G. S.; Hassan, M.; Laureti, S.; Rinaldi, C.; Fagiani, F.; Barucca, G.; Schmidt, N.; Zabila, Y.; Kosub, T.; Illing, R.; Volkov, O.; Vladymyrskyi, I.; Fassbender, J.; Albrecht, M.; Varvaro, G.; Makarov, D.
Classificazione: 1 Contributo su Rivista
Abstract: Artificial magnetoception is a new and yet to be explored path for humans to interact with the surroundings. This technology is enabled by thin film magnetic field sensors embedded in a soft and flexible format to constitute magnetosensitive electronic skins (e-skins). Being limited by the sensitivity to in-plane magnetic fields, magnetosensitive e-skins are restricted to basic proximity and angle sensing and are not used as switches or logic elements of interactive wearable electronics. Here, a novel magnetoreceptive platform for on-skin touchless interactive electronics based on flexible spin valve switches with sensitivity to out-of-plane magnetic fields is demonstrated. The technology relies on all-metal Co/Pd-based spin valves with a synthetic antiferromagnet possessing perpendicular magnetic anisotropy. The flexible magnetoreceptors act as logic elements, namely momentary and permanent (latching) switches. The switches maintain their performance even upon bending to a radius of less than 3.5 mm and withstand repetitive bending for hundreds of cycles. Here, flexible switches are integrated in on-skin interactive electronics and their performance as touchless human-machine interfaces is demonstrated, which are intuitive to use, energy efficient, and insensitive to external magnetic disturbances. This technology offers qualitatively new functionalities for electronic skins and paves the way towards full-fledged on-skin touchless interactive electronics.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/289594

Influence of the thermomechanical characteristics of low-density polyethylene substrates on the thermoresistive properties of graphite nanoplatelet coatings
COATINGS
Autore/i: Coscia, U.; Longo, A.; Palomba, M.; Sorrentino, A.; Barucca, G.; Di Bartolomeo, A.; Urban, F.; Ambrosone, G.; Carotenuto, G.
Classificazione: 1 Contributo su Rivista
Abstract: Morphological, structural, and thermoresistive properties of films deposited on low-density polyethylene (LDPE) substrates are investigated for possible application in flexible electronics. Scanning and transmission electron microscopy analyses, and X-ray diffraction measurements show that the films consist of overlapped graphite nanoplatelets (GNP) each composed on average of 41 graphene layers. Differential scanning calorimetry and dynamic-mechanical-thermal analysis indicate that irreversible phase transitions and large variations of mechanical parameters in the polymer substrates can be avoided by limiting the temperature variations between −40 and 40◦ C. Electrical measurements performed in such temperature range reveal that the resistance of GNP films on LDPE substrates increases as a function of the temperature, unlike the behavior of graphite-based materials in which the temperature coefficient of resistance is negative. The explanation is given by the strong influence of the thermal expansion properties of the LDPE substrates on the thermo-resistive features of GNP coating films. The results show that, narrowing the temperature range from 20 to 40◦ C, the GNP on LDPE samples can work as temperature sensors having linear temperature-resistance relationship, while keeping constant the temperature and applying mechanical strains in the 0–4.2 × 10−3 range, they can operate as strain gauges with a gauge factor of about 48.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/289592

Complex correlations between microstructure and magnetic behavior in SrFe12O19 hexaferrite nanoparticles
SCIENTIFIC REPORTS
Autore/i: Maltoni, P.; Ivanov, S. A.; Barucca, G.; Varvaro, G.; Peddis, D.; Mathieu, R.
Classificazione: 1 Contributo su Rivista
Abstract: The magnetic properties of SrFe12O19 (SFO) hard hexaferrites are governed by the complex relation to its microstructure, determining their relevance for permanent magnets´ applications. A set of SFO nanoparticles obtained by sol–gel self-combustion synthesis was selected for an in-depth structural X-Rays powder diffraction (XRPD) characterization by means of G(L) line-profile analysis. The obtained crystallites´ size distribution reveal a clear dependence of the size along the [001] direction on the synthesis approach, resulting in the formation of platelet-like crystallites. In addition, the size of the SFO nanoparticles was determined by transmission electron microscopy (TEM) analysis and the average number of crystallites within a particle was estimated. These results have been evaluated to illustrate the formation of single-domain state below a critical value, and the activation volume was derived from time dependent magnetization measurements, aiming to clarify the reversal magnetization process of hard magnetic materials.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/295104

Study of excited Ξ baryons with the PANDA detector
THE EUROPEAN PHYSICAL JOURNAL. A, HADRONS AND NUCLEI
Autore/i: Barucca, G.; Davi', F.; Lancioni, G.; Mengucci, P.; Montalto, L.; Natali, P. P.; Paone, N.; Rinaldi, D.; Scalise, L.; Krusche, B.; Steinacher, M.; Li, Z.; Liu, C.; Liu, B.; Shen, X.; Sun, S.; Zhao, G.; Zhao, J.; Albrecht, M.; Alkakhi, W.; Bökelmann, S.; Coen, S.; Feldbauer, F.; Fink, M.; Frech, J.; Freudenreich, V.; Fritsch, M.; Grochowski, J.; Hagdorn, R.; Heinsius, F. H.; Held, T.; Holtmann, T.; Keshk, I.; Koch, H.; Kopf, B.; Kümmel, M.; Küner, M.; Li, J.; Linzen, L.; Maldaner, S.; Oppotsch, J.; Pankonin, S.; Pelizä, M.; Pflüger, S.; Reher, J.; Reicherz, G.; Schnier, C.; Steinke, M.; Triffterer, T.; Wenzel, C.; Wiedner, U.; Denizli, H.; Er, N.; Keskin, U.; Yerlikaya, S.; Yilmaz, A.; Bec, R.; Chauhan, V.; Hammann, C.; Hartmann, J.; Ketzer, B.; Müllers, J.; Salisbury, B.; Schmidt, C.; Thoma, U.; Urban, M.; Bianconi, A.; Bragadireanu, M.; Pantea, D.; Domagala, M.; Filo, G.; Lisowski, E.; Lisowski, F.; Michałek, M.; Poznanski, P.; Płazek, J.; Korcyl, K.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Firlej, M.; Fiutowski, T.; Idzik, M.; Moron, J.; Swientek, K.; Terlecki, P.; Korcyl, G.; Lalik, R.; Malige, A.; Moskal, P.; Nowakowski, K.; Przygoda, W.; Rathod, N.; Salabura, P.; Smyrski, J.; Augustin, I.; Böhm, R.; Lehmann, I.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Flemming, H.; Gerhardt, A.; Götzen, K.; Heinz, A.; Jiang, P.; Karabowicz, R.; Koch, S.; Kurilla, U.; Lehmann, D.; Lühning, J.; Lynen, U.; Orth, H.; Peters, K.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Voss, B.; Wieczorek, P.; Abazov, V.; Alexeev, G.; Barabanov, M. Yu.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Galoyan, A.; Golovanov, G.; Koshurnikov, E. K.; Lobanov, Y. Yu.; Olshevskiy, A. G.; Piskun, A. A.; Samartsev, A.; Shimanski, S.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Tokmenin, V.; Uzhinsky, V.; Verkheev, A.; Vodopianov, A.; Zhuravlev, N. I.; Watts, D.; Böhm, M.; Eyrich, W.; Lehmann, A.; Miehling, D.; Pfaffinger, M.; Seth, K.; Xiao, T.; Ali, A.; Hamdi, A.; Himmelreich, M.; Krebs, M.; Nakhoul, S.; Nerling, F.; Gianotti, P.; Lucherini, V.; Bracco, G.; Bodenschatz, S.; Brinkmann, K. T.; Brück, L.; Diehl, S.; Dormenev, V.; Düren, M.; Erlen, T.; Hahn, C.; Hayrapetyan, A.; Hofmann, J.; Kegel, S.; Khalid, F.; Köseoglu, I.; Kripko, A.; Kühn, W.; Metag, V.; Moritz, M.; Nanova, M.; Novotny, R.; Orsich, P.; Pereira-de-Lira, J.; Sachs, M.; Schmidt, M.; Schubert, R.; Strickert, M.; Wasem, T.; Zaunick, H. G.; Tomasi-Gustafsson, E.; Glazier, D.; Ireland, D.; Seitz, B.; Kappert, R.; Kavatsyuk, M.; Loehner, H.; Messchendorp, J.; Rodin, V.; Kalita, K.; Huang, G.; Liu, D.; Peng, H.; Qi, H.; Sun, Y.; Zhou, X.; Kunze, M.; Azizi, K.; Olgun, A. T.; Tavukoglu, Z.; Derichs, A.; Dosdall, R.; Esmail, W.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Jokhovets, L.; Kannika, J.; Kulessa, P.; Orfanitski, S.; Pérez-Andrade, G.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Rosenthal, E.; Schadmand, S.; Schmitz, R.; Scholl, A.; Sefzick, T.; Serdyuk, V.; Stockmanns, T.; Veretennikov, D.; Wintz, P.; Wüstner, P.; Xu, H.; Zhou, Y.; Cao, X.; Hu, Q.; Liang, Y.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Lauth, W.; Leithoff, H. H.; Merkel, H.; Müller, U.; Petersen, J.; Pochodzalla, J.; Schlimme, S.; Sfienti, C.; Thiel, M.; Bleser, S.; Bölting, M.; Capozza, L.; Dbeyssi, A.; Ehret, A.; Klasen, R.; Kliemt, R.; Maas, F.; Motzko, C.; Noll, O.; Rodríguez Piñeiro, D.; Schupp, F.; Steinen, M.; Wolff, S.; Zimmermann, I.; Kazlou, D.; Korzhik, M.; Missevitch, O.; Balanutsa, P.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Golubev, A.; Kantsyrev, A.; Kirin, D. Y.; Kristi, N.; Ladygina, E.; Luschevskaya, E.; Matveev, V. A.; Panjushkin, V.; Stavinskiy, A. V.; Balashoff, A.; Boukharov, A.; Bukharova, M.; Malyshev, O.; Vishnevsky, E.; Bonaventura, D.; Brand, P.; Hetz, B.; Hüsken, N.; Kellers, J.; Khoukaz, A.; Klostermann, D.; Mannweiler, C.; Vestrick, S.; Bumrungkoh, D.; Herold, C.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Manasatitpong, K.; Nasawad, T.; Pongampai, S.; Simantathammakul, T.; Srisawad, P.; Wongprachanukul, N.; Yan, Y.; Yu, C.; Zhang, X.; Zhu, W.; Antokhin, E.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, V. E.; Kuyanov, I. A.; Pivovarov, S.; Pyata, E.; Tikhonov, Y.; Blinov, A. E.; Kononov, S.; Kravchenko, E. A.; Lattery, M.; Boca, G.; Duda, D.; Finger, M.; Finger Jr., M.; Kveton, A.; Pesek, M.; Peskova, M.; Prochazka, I.; Slunecka, M.; Volf, M.; Gallus, P.; Jary, V.; Korchak, O.; Marcisovsky, M.; Neue, G.; Novy, J.; Tomasek, L.; Tomasek, M.; Virius, M.; Vrba, V.; Abramov, V.; Bukreeva, S.; Chernichenko, S.; Derevschikov, A.; Ferapontov, V.; Goncharenko, Y.; Levin, A.; Maslova, E.; Melnik, Y.; Meschanin, A.; Minaev, N.; Mochalov, V.; Moiseev, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Belostotski, S.; Fedotov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Preston, M.; Tegner, P. E.; Wölbing, D.; Cederwall, B.; Gandhi, K.; Rai, A. K.; Godre, S.; Crede, V.; Dobbs, S.; Eugenio, P.; Calvo, D.; De Remigis, P.; Filippi, A.; Mazza, G.; Wheadon, R.; Iazzi, F.; Lavagno, A.; Bussa, M. P.; Spataro, S.; Akram, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Regina, J.; Rieger, J.; Schönning, K.; Wolke, M.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Tarasiuk, J.; Wronka, S.; Zwieglinski, B.; Amsler, C.; Bühler, P.; Marton, J.; Zimmermann, S.
Classificazione: 1 Contributo su Rivista
Abstract: The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment PANDA will provide direct access to final states containing a ΞΞ pair, for which production cross sections up to μb are expected in ¯pp reactions.With a luminosity of L = 1031 cm−2 s−1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼ 106 events/day. With a nearly 4π detector acceptance, PANDA will thus be a hyperon factory. In this study, reactions of the type ¯pp → Ξ+Ξ∗− as well as ¯pp → Ξ∗+Ξ− with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/289859

Hybrid Spinel Iron Oxide Nanoarchitecture Combining Crystalline and Amorphous Parent Material
JOURNAL OF PHYSICAL CHEMISTRY. C
Autore/i: Slimani, S.; Concas, G.; Congiu, F.; Barucca, G.; Yaacoub, N.; Talone, A.; Smari, M.; Dhahri, E.; Peddis, D.; Muscas, G.
Classificazione: 1 Contributo su Rivista
Abstract: When preparing nanostructured magnetic materials, the presence of an amorphous component is often considered a weakness of the synthesis method and a waste of material. This stems because the amorphous fraction is often pictured as a "dead"magnetic component, showing little to no contribution to the magnetic properties, for example, saturation magnetization. For this reason, additional steps are employed after the main synthesis process to reduce or isolate and remove the amorphous phase from the "optimal"crystalline product. Here, we propose a hybrid-structured nanoarchitecture that combines crystalline cobalt ferrite and the amorphous parent material. The latter contributes partially to the total magnetic moment but exhibits a magnetic anisotropy much larger than the crystalline bulk parent material. With the information obtained from an in-depth structural and magnetic characterization, a micromagnetic model is created, allowing identifying the contribution of each component elucidating the active role of the amorphous phase. The extremely low cost, minimal complexity, and high yield of the synthesis process make this hybrid design of large interest for technological applications.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/292445

Perpendicularly magnetized Co/Pd-based magneto-resistive heterostructures on flexible substrates
NANOSCALE ADVANCES
Autore/i: Hassan, M.; Laureti, S.; Rinaldi, C.; Fagiani, F.; Varotto, S.; Barucca, G.; Schmidt, N. Y.; Varvaro, G.; Albrecht, M.
Classificazione: 1 Contributo su Rivista
Abstract: Flexible magneto-resistive heterostructures have received a great deal of attention over the past few years as they allow for new product paradigms that are not possible with conventional rigid substrates. While the progress and development of systems with longitudinal magnetic anisotropy on non-planar substrates has been remarkable, flexible magneto-resistive heterostructures with perpendicular magnetic anisotropy (PMA) have never been studied despite the possibility to obtain additional functionality and improved performance. To fill this gap, flexible PMA Co/Pd-based giant magneto-resistive (GMR) spin-valve stacks were prepared by using an innovative transfer-and-bonding strategy exploiting the low adhesion of a gold underlayer to SiOx/Si(100) substrates. The approach allows overcoming the limits of the direct deposition on commonly used polymer substrates, whose high surface roughness and low melting temperature could hinder the growth of complex heterostructures with perpendicular magnetic anisotropy. The obtained PMA flexible spin-valves show a sizeable GMR ratio (∼1.5%), which is not affected by the transfer process, and a high robustness against bending as indicated by the slight change of the magneto-resistive properties upon bending, thus allowing for their integration on curved surfaces and the development of a novel class of advanced devices based on flexible magneto-resistive structures with perpendicular magnetic anisotropy. Besides endowing the family of flexible electronics with PMA magneto-resistive heterostructures, the exploitation of the results might apply to high temperature growth processes and to the fabrication of other functional and flexible multilayer materials engineered at the nanoscale.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/292443

Tuning the Magnetic Properties of Hard-Soft SrFe12O19/CoFe2O4Nanostructures via Composition/Interphase Coupling
JOURNAL OF PHYSICAL CHEMISTRY. C
Autore/i: Maltoni, P.; Sarkar, T.; Barucca, G.; Varvaro, G.; Locardi, F.; Peddis, D.; Mathieu, R.
Classificazione: 1 Contributo su Rivista
Abstract: Magnetic nanocomposites (NCs) are extremely appealing for a wide range of energy-related technological applications, specifically as building blocks for next-generation permanent magnets. The design of such nanostructures requires precise chemical synthesis methods, which will permit the fine-tuning of the magnetic properties. Here we present an in-depth structural, morphological and magnetic characterization of ferrite-based nanostructures obtained through a bottom-up sol-gel approach. The combination of the high coercivity of a hard phase SrFe12O19 (SFO) and the high saturation magnetization of a soft phase, CoFe2O4 (CFO), allowed us to develop exchange-coupled bimagnetic NCs. A symbiotic effect is observed in a SFO/CFO nanocomposite, as the unique oriented growth of SFO prevents grain growth of the CFO, thus restricting the crystallite size of both. Through X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and magnetic measurements we clarify the relationship between the distribution and size of hard/soft particles, the optimization of interfaces and the obtained uniform magnetic response. This study allowed us to establish the potentiality of hard/soft SFO/CFO nanostructures in current permanent magnet technology.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/289593

Feasibility studies for the measurement of time-like proton electromagnetic form factors from ¯p p → μ+μ− at PANDA at FAIR
THE EUROPEAN PHYSICAL JOURNAL. A, HADRONS AND NUCLEI
Autore/i: Barucca, Gianni; Davi', F.; Lancioni, G.; Mengucci, P.; Montalto, L.; Natali, P. P.; Paone, N.; Rinaldi, D.; Scalise, L.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Cao, N.; Liu, Z.; Liu, C.; Liu, B.; Shen, X.; Sun, S.; Tao, J.; Xiong, X. A.; Zhao, G.; Zhao, J.; Albrecht, M.; Alkakhi, W.; Bökelmann, S.; Coen, S.; Feldbauer, F.; Fink, M.; Frech, J.; Freudenreich, V.;   , ; M. Fritsch,   ; J. Grochowski,   ; R. Hagdorn,   ; F. H. Heinsius,   ; T. Held,   ; T. Holtmann,   ; I. Keshk,   ; H. Koch,   ; B. Kopf,   ; M. Kuhlmann,   ; M. Kümmel,   ; M. Küßner,   ; J. Li,   ; L. Linzen,   ; S. Maldaner,   ; J. Oppotsch,   ; S. Pankonin,   ; M. Pelizäus,   ; S. Pflüger,   ; A. Pitka,   ; J. Reher,   ; G. Reicherz,   ; C. Schnier,   ; M. Steinke,   ; T. Triffterer,   ; C. Wenzel,   ; Wiedner, U.; Denizli, H.;   , ; N. Er,   ; U. Keskin,   ; A. T. Olgun,   ; Yerlikaya, S.; Yilmaz, A.; Beck, R.;   , ; C. Hammann,   ; J. Hartmann,   ; B. Ketzer,   ; J. Müllers,   ; M. Rossbach,   ; B. Salisbury,   ; C. Schmidt,   ; U. Thoma,   ; Urban, M.; Bianconi, A.; Bragadireanu, M.; Pantea, D.; Domagala, M.;   , ; G. Filo,   ; E. Lisowski,   ; F. Lisowski,   ; M. Michałek,   ; Poznański, P.; Płażek, J.; Korcyl, K.;   , ; A. Kozela,   ; P. Lebiedowicz,   ; K. Pysz,   ; W. Schäfer,   ; Szczurek, A.; Firlej, M.;   , ; T. Fiutowski,   ; M. Idzik,   ; J. Moron,   ; Swientek, K.; Terlecki, P.; Korcyl, G.;   , ; R. Lalik,   ; A. Malige,   ; P. Moskal,   ; K. Nowakowski,   ; W. Przygoda,   ; N. Rathod,   ; Z. Rudy,   ; Salabura, P.; Smyrski, J.; Augustin, I.;   , ; R. Böhm,   ; I. Lehmann,   ; Schmitt, L.; Varentsov, V.; Al-Turany, M.;   , ; A. Belias,   ; H. Deppe,   ; R. Dzhygadlo,   ; H. Flemming,   ; A. Gerhardt,   ; K. Götzen,   ; A. Heinz,   ; P. Jiang,   ; R. Karabowicz,   ; S. Koch,   ; U. Kurilla,   ; D. Lehmann,   ; J. Lühning,   ; U. Lynen,   ; H. Orth,   ; K. Peters,   ; T. Saito,   ; G. Schepers,   ; C. J. Schmidt,   ; C. Schwarz,   ; J. Schwiening,   ; A. Täschner,   ; M. Traxler,   ; Voss, B.; Wieczorek, P.; Abazov, V.;   , ; G. Alexeev,   ; V. A. Arefiev,   ; V. Astakhov,   ; M. Yu. Barabanov,   ; B. V. Batyunya,   ; V. Kh. Dodokhov,   ; A. Efremov,   ; A. Fechtchenko,   ; A. Galoyan,   ; G. Golovanov,   ; E. K. Koshurnikov,   ; Y. Yu. Lobanov,   ; A. G. Olshevskiy,   ; A. A. Piskun,   ; A. Samartsev,   ; S. Shimanski,   ; N. B. Skachkov,   ; A. N. Skachkova,   ; E. A. Strokovsky,   ; V. Tokmenin,   ; V. Uzhinsky,   ; A. Verkheev,   ; Vodopianov, A.; Zhuravlev, N. I.; Branford, D.; Watts, D.; Böhm, M.;   , ; W. Eyrich,   ; A. Lehmann,   ; Miehling, D.; Pfaffinger, M.; Quin, N.;   , ; L. Robison,   ; Seth, K.; Xiao, T.; Bettoni, D.; Ali, A.;   , ; A. Hamdi,   ; M. Himmelreich,   ; M. Krebs,   ; Nakhoul, S.; Nerling, F.; Belousov, A.;   , ; I. Kisel,   ; G. Kozlov,   ; Pugach, M.; Zyzak, M.; Bianchi, N.;   , ; Gianotti, P.; Lucherini, V.; Bracco, G.; Bettner, Y.;   , ; S. Bodenschatz,   ; K. T. Brinkmann,   ; L. Brück,   ; S. Diehl,   ; V. Dormenev,   ; M. Düren,   ; T. Erlen,   ; K. Föhl,   ; C. Hahn,   ; A. Hayrapetyan,   ; J. Hofmann,   ; S. Kegel,   ; M. Kesselkaul,   ; I. Köseoglu,   ; A. Kripko,   ; W. Kühn,   ; J. S. Lange,   ; V. Metag,   ; M. Moritz,   ; M. Nanova,   ; R. Novotny,   ; P. Orsich,   ; J. Pereira-de-Lira,   ; M. Peter,   ; M. Sachs,   ; M. Schmidt,   ; R. Schubert,   ; H. Stenzel,   ; M. Straube,   ; M. Strickert,   ; U. Thöring,   ; T. Wasem,   ; Wohlfahrt, B.; Zaunick, H. G.; Tomasi-Gustafsson, E.; Glazier, D.;   , ; Ireland, D.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Kappert, R.;   , ; M. Kavatsyuk,   ; H. Loehner,   ; J. Messchendorp,   ; V. Rodin,   ; Schakel, P.; Vejdani, S.; Dutta, K.; Kalita, K.; Huang, G.;   , ; D. Liu,   ; H. Peng,   ; H. Qi,   ; Sun, Y.; Zhou, X.; Kunze, M.; Azizi, K.; Tavukoglu, Z.; Derichs, A.;   , ; R. Dosdall,   ; W. Esmail,   ; A. Gillitzer,   ; F. Goldenbaum,   ; D. Grunwald,   ; L. Jokhovets,   ; J. Kannika,   ; P. Kulessa,   ; S. Orfanitski,   ; G. Pérez Andrade,   ; D. Prasuhn,   ; E. Prencipe,   ; J. Pütz,   ; J. Ritman,   ; E. Rosenthal,   ; S. Schadmand,   ; R. Schmitz,   ; A. Scholl,   ; T. Sefzick,   ; V. Serdyuk,   ; T. Stockmanns,   ; D. Veretennikov,   ; P. Wintz,   ; P. Wüstner,   ; Xu, H.; Zhou, Y.; Cao, X.;   , ; Q. Hu,   ; Z. Li,   ; H. Li,   ; Liang, Y.; Ma, X.; Rigato, V.; Isaksson, L.; Achenbach, P.;   , ; O. Corell,   ; A. Denig,   ; M. Distler,   ; M. Hoek,   ; W. Lauth,   ; H. H. Leithoff,   ; Z. Liu,   ; H. Merkel,   ; U. Müller,   ; J. Pochodzalla,   ; S. Schlimme,   ; C. Sfienti,   ; Thiel, M.; Zambrana, M.; Ahmed, S.;   , ; S. Bleser,   ; M. Bölting,   ; L. Capozza,   ; A. Dbeyssi,   ; A. Ehret,   ; R. Klasen,   ; R. Kliemt,   ; F. Maas,   ; C. Motzko,   ; O. Noll,   ; D. Rodríguez Piñeiro,   ; F. Schupp,   ; M. Steinen,   ; Wolff, S.; Zimmermann, I.; Fedorov, A.;   , ; D. Kazlou,   ; Korzhik, M.; Missevitch, O.; Balanutsa, P.;   , ; V. Chernetsky,   ; A. Demekhin,   ; A. Dolgolenko,   ; P. Fedorets,   ; A. Gerasimov,   ; A. Golubev,   ; V. Goryachev,   ; A. Kantsyrev,   ; D. Y. Kirin,   ; N. Kristi,   ; E. Ladygina,   ; E. Luschevskaya,   ; V. A. Matveev,   ; Panjushkin, V.; Stavinskiy, A. V.; Balashoff, A.;   , ; Boukharov, A.; Malyshev, O.; Basant, K. N.;   , ; H. Kumawat,   ; B. Roy,   ; Saxena, A.; Yogesh, S.; Bonaventura, D.;   , ; P. Brand,   ; C. Fritzsch,   ; S. Grieser,   ; C. Hargens,   ; A. K. Hergemöller,   ; B. Hetz,   ; N. Hüsken,   ; J. Kellers,   ; A. Khoukaz,   ; Mannweiler, C.; Vestrick, S.; Bumrungkoh, D.;   , ; C. Herold,   ; K. Khosonthongkee,   ; C. Kobdaj,   ; A. Limphirat,   ; K. Manasatitpong,   ; T. Nasawad,   ; S. Pongampai,   ; T. Simantathammakul,   ; P. Srisawad,   ; Wongprachanukul, N.; Yan, Y.; Yu, C.;   , ; Zhang, X.; Zhu, W.; Blinov, A. E.;   , ; Kononov, S.; Kravchenko, E. A.; Antokhin, E.;   , ; A. Yu. Barnyakov,   ; K. Beloborodov,   ; V. E. Blinov,   ; I. A. Kuyanov,   ; S. Pivovarov,   ; Pyata, E.; Tikhonov, Y.; Hunter, G.;   , ; Lattery, M.; Pace, H.; Boca, G.; Duda, D.; Finger, M.;   , ; Finger, M.;   , Jr.; A. Kveton,   ; M. Pesek,   ; M. Peskova,   ; I. Prochazka,   ; Slunecka, M.; Volf, M.; Gallus, P.;   , ; V. Jary,   ; O. Korchak,   ; M. Marcisovsky,   ; G. Neue,   ; J. Novy,   ; L. Tomasek,   ; M. Tomasek,   ; Virius, M.; Vrba, V.; Abramov, V.;   , ; S. Bukreeva,   ; S. Chernichenko,   ; A. Derevschikov,   ; V. Ferapontov,   ; Y. Goncharenko,   ; A. Levin,   ; E. Maslova,   ; Y. Melnik,   ; A. Meschanin,   ; N. Minaev,   ; V. Mochalov,   ; V. Moiseev,   ; D. Morozov,   ; L. Nogach,   ; S. Poslavskiy,   ; A. Ryazantsev,   ; S. Ryzhikov,   ; P. Semenov,   ; I. Shein,   ; A. Uzunian,   ; Vasiliev, A.; Yakutin, A.; Roy, U.; Yabsley, B.; Belostotski, S.;   , ; G. Fedotov,   ; G. Gavrilov,   ; A. Izotov,   ; S. Manaenkov,   ; Miklukho, O.; Zhdanov, A.; Atac, A.;   , ; Bäck, T.; Cederwall, B.; Makonyi, K.;   , ; M. Preston,   ; Tegner, P. E.; Wölbing, D.; Gandhi, K.; Rai, A. K.; Godre, S.; Crede, V.;   , ; S. Dobbs,   ; Eugenio, P.; Lersch, D.; Calvo, D.;   , ; P. De Remigis,   ; A. Filippi,   ; G. Mazza,   ; Rivetti, A.; Wheadon, R.; Bussa, M. P.; Spataro, S.; Iazzi, F.; Lavagno, A.; Martin, A.; Akram, A.;   , ; H. Calen,   ; W. Ikegami Andersson,   ; T. Johansson,   ; A. Kupsc,   ; P. Marciniewski,   ; M. Papenbrock,   ; J. Regina,   ; J. Rieger,   ; Schönning, K.; Wolke, M.; Pothodi Chackara, V.; Chlopik, A.;   , ; G. Kesik,   ; D. Melnychuk,   ; J. Tarasiuk,   ; M. Wojciechowski,   ; Wronka, S.; Zwieglinski, B.; Amsler, C.;   , ; P. Bühler,   ; J. Marton,   ; W. Nalti,   ; D. Steinschaden,   ; E. Widmann,   ; S. Zimmermann, J. Zmeskal
Classificazione: 1 Contributo su Rivista
Abstract: This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, || | G E | and || | G M | , using the ¯→+− p ¯ p → μ + μ − reaction at P⎯⎯⎯ANDA P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P⎯⎯⎯ANDA P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is ¯→+− p ¯ p → π + π − , due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286840

Wavy graphene sheets from electrochemical sewing of corannulene
CHEMICAL SCIENCE
Autore/i: Bruno, C; Ussano, E; Barucca, G; Vanossi, D; Valenti, G; Jackson, Ea; Goldoni, A; Litti, L; Fermani, S; Pasquali, L; Meneghetti, M; Fontanesi, C; Scott, Lt; Paolucci, F; Marcaccio, M
Classificazione: 1 Contributo su Rivista
Abstract: The presence of non-hexagonal rings in the honeycomb carbon arrangement of graphene produces rippled graphene layers with valuable chemical and physical properties. In principle, a bottom-up approach to introducing distortion from planarity of a graphene sheet can be achieved by careful insertion of curved polyaromatic hydrocarbons during the growth of the lattice. Corannulene, the archetype of such non-planar polyaromatic hydrocarbons, can act as an ideal wrinkling motif in 2D carbon nanostructures. Herein we report an electrochemical bottom-up method to obtain egg-box shaped nanographene structures through a polycondensation of corannulene that produces a new conducting layered material. Characterization of this new polymeric material by electrochemistry, spectroscopy, electron microscopy (SEM and TEM), scanning probe microscopy, and laser desorption-ionization time of flight mass spectrometry provides strong evidence that the anodic polymerization of corannulene, combined with electrochemically induced oxidative cyclodehydrogenations (Scholl reactions), leads to polycorannulene with a wavy graphene-like structure.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/290578

Combined Bottom-Up and Top-Down Approach for Highly Ordered One-Dimensional Composite Nanostructures for Spin Insulatronics
ACS APPLIED MATERIALS & INTERFACES
Autore/i: Datt, G.; Kotnana, G.; Maddu, R.; Vallin, O.; Joshi, D. C.; Peddis, D.; Barucca, G.; Kamalakar, M. V.; Sarkar, T.
Classificazione: 1 Contributo su Rivista
Abstract: Engineering magnetic proximity effects-based devices requires developing efficient magnetic insulators. In particular, insulators, where magnetic phases show dramatic changes in texture on the nanometric level, could allow us to tune the proximity-induced exchange splitting at such distances. In this paper, we report the fabrication and characterization of highly ordered two-dimensional arrays of LaFeO3 (LFO)-CoFe2O4 (CFO) biphasic magnetic nanowires, grown on silicon substrates using a unique combination of bottom-up and top-down synthesis approaches. The regularity of the patterns was confirmed using atomic force microscopy and scanning electron microscopy techniques, whereas magnetic force microscopy images established the magnetic homogeneity of the patterned nanowires and absence of any magnetic debris between the wires. Transmission electron microscopy shows a close spatial correlation between the LFO and CFO phases, indicating strong grain-to-grain interfacial coupling, intrinsically different from the usual core-shell structures. Magnetic hysteresis loops reveal the ferrimagnetic nature of the composites up to room temperature and the presence of a strong magnetic coupling between the two phases, and electrical transport measurements demonstrate the strong insulating behavior of the LFO-CFO composite, which is found to be governed by Mott-variable range hopping conduction mechanisms. A shift in the Raman modes in the composite sample compared to those of pure CFO suggests the existence of strain-mediated elastic coupling between the two phases in the composite sample. Our work offers ordered composite nanowires with strong interfacial coupling between the two phases that can be directly integrated for developing multiphase spin insulatronic devices and emergent magnetic interfaces.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/292442

Spinel iron oxide by the co-precipitation method: Effect of the reaction atmosphere
APPLIED SCIENCES
Autore/i: Slimani, S.; Meneghini, C.; Abdolrahimi, M.; Talone, A.; Murillo, J. P. M.; Barucca, G.; Yaacoub, N.; Imperatori, P.; Illes, E.; Smari, M.; Dhahri, E.; Peddis, D.
Classificazione: 1 Contributo su Rivista
Abstract: Synthesis atmosphere (i.e., air and nitrogen) effects on the physical properties and formation mechanism of spinel iron oxide nanoparticles prepared via the co-precipitation method have been investigated using a multi-technique approach. The obtained magnetic nanoparticles (MNPs) were characterized using the X-ray diffraction, transmission electron microscopy (TEM), SQUID magnetometry, Mössbauer spectroscopy and X-ray absorption near-edge Structure spectroscopy techniques. The synthesis procedure leads to the formation of a spinel structure with an average crys-tallite size of 9.0(9) nm. The morphology of the particles synthetized under an inert atmosphere was quasi-spherical, while the nanoparticles prepared in air present a faceted shape. The small differences observed in morphological properties are explained by the influence of the reaction atmosphere on the formation mechanism of the MNPs. The magnetic characterization indicates that both samples exhibit superparamagnetic behavior at 300 K. The investigation by means of the Langevin approach at 300 K also leads to equal values for the mean size of the magnetic cores (Dm). Additionally, the analysis of the Mössbauer spectra revealed the lack of spin disorder for both samples, resulting in a high saturation magnetization. The fit of XANES spectrum suggests that about 2/3 of the iron ions reside in a local environment close to that of γ-Fe2O3 and about 1/3 close to that of Fe3O4 for the sample synthetized in inert atmosphere.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/292444

The potential of $Lambda$ and $Chi^{-}$ studies with PANDA at FAIR
THE EUROPEAN PHYSICAL JOURNAL. A, HADRONS AND NUCLEI
Autore/i: Barucca, G.; Davi', F.; Lancioni, G.; Mengucci, P.; Montalto, L.; Natali, P. P.; Paone, N.; Rinaldi, D.; Scalise, L.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Cao, N.; Liu, Z.; Liu, C.; Liu, B.; Shen, X.; Sun, S.; Tao, J.; Xiong, X. A.; Zhao, G.; Zhao, J.; Albrecht, M.; Alkakhi, W.; Bökelmann, S.; Feldbauer, F.; Fink, M.; Frech, J.; Freudenreich, V.; Fritsch, M.; Hagdorn, R.; Heinsius, F. H.; Held, T.; Holtmann, T.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Küßner, M.; Li, J.; Mustafa, A.; Pelizäus, M.; Pitka, A.; Reher, J.; Reicherz, G.; Richter, M.; Schnier, C.; Sohl, L.; Steinke, M.; Triffterer, T.; Wenzel, C.; Wiedner, U.; Denizli, H.; Er, N.; Beck, R.; Hammann, C.; Hartmann, J.; Ketzer, B.; Müllers, J.; Rossbach, M.; Salisbury, B.; Schmidt, C.; Thoma, U.; Urban, M.; Bianconi, A.; Bragadireanu, M.; Pantea, D.; Domagala, M.; Filo, G.; Lisowski, E.; Lisowski, F.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Swientek, K.; Terlecki, P.; Korcyl, G.; Lalik, R.; Malige, A.; Moskal, P.; Nowakowski, K.; Przygoda, W.; Rathod, N.; Rudy, Z.; Salabura, P.; Smyrski, J.; Augustin, I.; Böhm, R.; Lehmann, I.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Flemming, H.; Gerhardt, A.; Götzen, K.; Heinz, A.; Jiang, P.; Karabowicz, R.; Koch, S.; Kurilla, U.; Lehmann, D.; Lühning, J.; Lynen, U.; Orth, H.; Peters, K.; Rieger, J.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Voss, B.; Wieczorek, P.; Abazov, V.; Alexeev, G.; Arefiev, V. A.; Astakhov, V.; Barabanov, M. Yu.; Batyunya, B. V.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Galoyan, A.; Golovanov, G.; Koshurnikov, E. K.; Lobanov, Y. Yu.; Olshevskiy, A. G.; Piskun, A. A.; Samartsev, A.; Shimanski, S.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Tokmenin, V.; Uzhinsky, V.; Verkheev, A.; Vodopianov, A.; Zhuravlev, N. I.; Branford, D.; Watts, D.; Böhm, M.; Eyrich, W.; Lehmann, A.; Miehling, D.; Pfaffinger, M.; Quin, N.; Robison, L.; Seth, K.; Xiao, T.; Bettoni, D.; Ali, A.; Hamdi, A.; Himmelreich, M.; Krebs, M.; Nakhoul, S.; Nerling, F.; Belousov, A.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Bianchi, N.; Gianotti, P.; Lucherini, V.; Bracco, G.; Bettner, Y.; Bodenschatz, S.; Brinkmann, K. T.; Brück, L.; Diehl, S.; Dormenev, V.; Düren, M.; Erlen, T.; Föhl, K.; Hahn, C.; Hayrapetyan, A.; Hofmann, J.; Kegel, S.; Kesselkaul, M.; Köseoglu, I.; Kripko, A.; Kühn, W.; Lange, J. S.; Metag, V.; Moritz, M.; Nanova, M.; Novotny, R.; Orsich, P.; Pereira-de-Lira, J.; Peter, M.; Sachs, M.; Schmidt, M.; Schubert, R.; Stenzel, H.; Straube, M.; Strickert, M.; Thöring, U.; Wasem, T.; Wohlfahrt, B.; Zaunick, H. G.; Tomasi-Gustafsson, E.; Glazier, D.; Ireland, D.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Kappert, R.; Kavatsyuk, M.; Loehner, H.; Messchendorp, J.; Rodin, V.; Schakel, P.; Vejdani, S.; Dutta, K.; Kalita, K.; Huang, G.; Liu, D.; Peng, H.; Qi, H.; Sun, Y.; Zhou, X.; Kunze, M.; Azizi, K.; Derichs, A.; Dosdall, R.; Esmail, W.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Jokhovets, L.; Kannika, J.; Kulessa, P.; Orfanitski, S.; Pérez Andrade, G.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Rosenthal, E.; Schadmand, S.; Schmitz, R.; Scholl, A.; Sefzick, T.; Serdyuk, V.; Stockmanns, T.; Veretennikov, D.; Wintz, P.; Wüstner, P.; Xu, H.; Zhou, Y.; Cao, X.; Hu, Q.; Li, Z.; Li, H.; Liang, Y.; Ma, X.; Rigato, V.; Isaksson, L.; Achenbach, P.; Aycock, A.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Lauth, W.; Leithoff, H. H.; Liu, Z.; Merkel, H.; Müller, U.; Pochodzalla, J.; Schlimme, S.; Sfienti, C.; Thiel, M.; Zambrana, M.; Ahmed, S.; Bleser, S.; Bölting, M.; Capozza, L.; Dbeyssi, A.; Ehret, A.; Grasemann, P.; Klasen, R.; Kliemt, R.; Maas, F.; Maldaner, S.; Morales Morales, C.; Motzko, C.; Noll, O.; Pflüger, S.; Rodríguez Piñeiro, D.; Schupp, F.; Steinen, M.; Wolff, S.; Zimmermann, I.; Fedorov, A.; Kazlou, D.; Korzhik, M.; Missevitch, O.; Balashoff, A.; Boukharov, A.; Malyshev, O.; Balanutsa, P.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Golubev, A.; Goryachev, V.; Kantsyrev, A.; Kirin, D. Y.; Kristi, N.; Ladygina, E.; Luschevskaya, E.; Matveev, V. A.; Panjushkin, V.; Stavinskiy, A. V.; Basant, K. N.; Kumawat, H.; Roy, B.; Saxena, A.; Yogesh, S.; Bonaventura, D.; Brand, P.; Fritzsch, C.; Grieser, S.; Hargens, C.; Hergemöller, A. K.; Hetz, B.; Hüsken, N.; Kellers, J.; Khoukaz, A.; Bumrungkoh, D.; Herold, C.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Manasatitpong, K.; Nasawad, T.; Pongampai, S.; Simantathammakul, T.; Srisawad, P.; Wongprachanukul, N.; Yan, Y.; Yu, C.; Zhang, X.; Zhu, W.; Blinov, A. E.; Kononov, S.; Kravchenko, E. A.; Antokhin, E.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, V. E.; Kuyanov, I. A.; Pivovarov, S.; Pyata, E.; Tikhonov, Y.; Kunne, R.; Ramstein, B.; Hunter, G.; Lattery, M.; Pace, H.; Boca, G.; Duda, D.; Finger, M.; Finger Jr., M.; Kveton, A.; Pesek, M.; Peskova, M.; Prochazka, I.; Slunecka, M.; Volf, M.; Gallus, P.; Jary, V.; Korchak, O.; Marcisovsky, M.; Neue, G.; Novy, J.; Tomasek, L.; Tomasek, M.; Virius, M.; Vrba, V.; Abramov, V.; Bukreeva, S.; Chernichenko, S.; Derevschikov, A.; Ferapontov, V.; Goncharenko, Y.; Levin, A.; Maslova, E.; Melnik, Y.; Meschanin, A.; Minaev, N.; Mochalov, V.; Moiseev, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Roy, U.; Yabsley, B.; Belostotski, S.; Fedotov, G.; Gavrilov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Zhdanov, A.; Atac, A.; Bäck, T.; Cederwall, B.; Makonyi, K.; Preston, M.; Tegner, P. E.; Wölbing, D.; Gandhi, K.; Rai, A. K.; Godre, S.; Crede, V.; Dobbs, S.; Eugenio, P.; Lersch, D.; Calvo, D.; De Remigis, P.; Filippi, A.; Mazza, G.; Rivetti, A.; Wheadon, R.; Bussa, M. P.; Spataro, S.; Iazzi, F.; Lavagno, A.; Martin, A.; Akram, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Regina, J.; Schönning, K.; Wolke, M.; Diaz, J.; Pothodi Chackara, V.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Tarasiuk, J.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Amsler, C.; Bühler, P.; Kratochwil, N.; Marton, J.; Nalti, W.; Steinschaden, D.; Widmann, E.; Zimmermann, S.; Zmeskal, J.
Classificazione: 1 Contributo su Rivista
Abstract: The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: ¯→¯ and ¯→¯+−. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/289960

Exploring the magnetic properties and magnetic coupling in SrFe12O19/Co1-xZnxFe2O4 nanocomposites
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
Autore/i: Maltoni, P.; Sarkar, T.; Barucca, G.; Varvaro, G.; Peddis, D.; Mathieu, R.
Classificazione: 1 Contributo su Rivista
Abstract: Among hard/soft nanocomposites (NCs), ferrite-based materials are potentially promising for developing exchange-coupled systems, thus leading to enhanced magnetic properties. In this regard, we investigate the role of the synthesis approach in the development of SrFe12O19/CoFe2O4 (SFO/CFO) NCs, with special focus on tuning the magnetic features of the softer phase (CFO) by introducing Zn2+ in the spinel structure. X-ray powder diffraction (XRPD), transmission electron microscopy (TEM) and squid magnetometry were employed to clarify the relationship between morphology, size, and magnetic properties of the NCs, pointing out the feasibility of this method in obtaining successfully exchange-coupled systems. This work shows how optimizing the intrinsic magnetic properties of the CFO may be used to tune the extrinsic ones of the NCs. Despite the promising results in magnetic coupling, our study clearly confirms/strengthens that an enhancement of remanent magnetization is the most important factor for improving the magnetic performance.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/292441

Plasma-assisted deposition of iron oxide thin films for photoelectrochemical water splitting
PLASMA PROCESSES AND POLYMERS
Autore/i: Bosso, P.; Milella, A.; Barucca, G.; Mengucci, P.; Armenise, V.; Fanelli, F.; Giannuzzi, R.; Maiorano, V.; Fracassi, F.
Classificazione: 1 Contributo su Rivista
Abstract: Iron oxide thin films for photoelectrochemical (PEC) water splitting were deposited by radiofrequency sputtering of an iron target in argon/oxygen plasma mixtures, followed by thermal annealing. The chemical composition and structure of deposited film can be tuned by controlling the gas feed composition and the annealing temperature. The thermal treatment extensively improves the PEC water splitting performances of the films deposited at the lowest O2 percentages (0–1%), allowing to obtain photocurrent densities up to 1.20 mA/cm2 at 1.23 VRHE. Increasing the oxygen percentage in the plasma feed allows the direct growth of photoactive films; the best result is found for the hematite film produced at 50% O2, characterized by a photocurrent density of 0.21 at 1.23 VRHE.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/288861

Effect of oxygen content on the mechanical properties and plastic deformation mechanisms in the TWIP/TRIP Ti–12Mo alloy
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
Autore/i: Catanio Bortolan, C.; Contri Campanelli, L.; Paternoster, C.; Giguere, N.; Brodusch, N.; Bolfarini, C.; Gauvin, R.; Mengucci, P.; Barucca, G.; Mantovani, D.
Classificazione: 1 Contributo su Rivista
Abstract: In the last decades, biomaterials have improved the life and its quality for millions around the Globe. Titanium-based biomaterials have rapidly become the gold standard for bone contact applications. Despite their successful performance, their low strength-ductility trade-offs and work-hardening rates limit their use for example for the manufacture of vascular stents. Although a high strength-ductility trade-off and a high work-hardening rate were reported for the TWIP/TRIP Ti–12Mo alloy, strengthening strategies are required to approach its strength to the ones of Co–Cr alloys, main metallic materials used to produce stents. In this study, the investigated strengthening strategy was the increase of oxygen content from 0.04 to 0.18 wt% in the Ti–12Mo alloy. The effect of this increase on its microstructure, mechanical properties and plastic deformation mechanisms was studied. Athermal ω precipitates were observed throughout with the β matrix of both solution-treated alloys. X-Ray diffraction and transmission electron microscopy suggested that the quantity of ω phase was larger in the alloy with a higher oxygen content, contrasting with the common knowledge that O suppresses ω phase precipitation. Independently of oxygen content, {332}<113> twins and stress-induced martensite (SIM) α" occurred in the deformed microstructures. Based on the electron backscatter diffraction analyses, the area fraction of SIM α" decreased by increasing oxygen content. Although elongation decreased with this oxygen content increase, Ti–12Mo-0.18O exhibited a high true uniform elongation of 25% and a true ultimate tensile strength higher than the Ti–12Mo-0.04O alloy. Hardness and yield strength also increased by increasing oxygen content, while elastic modulus did not change.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/290576

Magnetic Nanoparticles Coated with (R)-9-Acetoxystearic Acid for Biomedical Applications
ACS OMEGA
Autore/i: Micheletti, G.; Boga, C.; Telese, D.; Cassani, M. C.; Boanini, E.; Nitti, P.; Ballarin, B.; Ghirri, A.; Barucca, G.; Rinaldi, D.
Classificazione: 1 Contributo su Rivista
Abstract: The well-known ability to selectively drive nanomagnetic materials coated with anticancer drugs into tumor cells suggested the synthesis and the characterization of magnetic nanoparticles (MNPs) functionalized with (R)-9-acetoxystearic acid, the acetic ester of (R)-9-hydroxystearic acid (9-HSA), an antiproliferative agent active against different cancer cells. The acyl chloride of (R)-9-acetoxystearic acid, synthesized in two steps from 9-HSA, was reacted with (3-aminopropyl)triethoxysilane, chosen as a linker between MNPs and the stearyl moiety. In the last step, the novel amide was bound to magnetite NPs by reaction with silyl groups. A detailed structural, chemical, and magnetic characterization of the obtained material proved that it possesses properties in agreement with the requirements for drug delivery, opening the possibility to further insights focused on the 9-HSA biomedical applications.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/282802

Novel mixed precursor approach to prepare multiferroic nanocomposites with enhanced interfacial coupling
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
Autore/i: Kotnana, G.; Sayed, F.; Joshi, D. C.; Barucca, G.; Peddis, D.; Mathieu, R.; Sarkar, T.
Classificazione: 1 Contributo su Rivista
Abstract: In the present work, we report the preparation of multiferroic PbZr0.52Ti0.48O3 (PZT)/CoFe2O4 (CFO) nanocomposites using a new synthesis technique that can maximize the surface area of contact, and hence, the interfacial coupling between the ferroelectric (PZT) and ferrimagnetic (CFO) phases. The samples have been characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the physical (magnetic and dielectric) properties have been investigated. XRD confirms the presence of the desired PZT and CFO phases in the samples without any undesired secondary phases. We also observe a reduction in the particle size of CFO in the nanocomposites as evidenced by a line broadening of the XRD reflections corresponding to the pure CFO phase. The nanocomposites show hysteresis loops and ferrimagnetic-like behaviors in their M vs H curves at room temperature, even for samples with very low fraction of the CFO phase. The coercivity of the nanocomposites is marginally larger compared to that of pure CFO, which can be due to the change in magnetic anisotropy of the CFO phase due to its reduced particle size in the nanocomposites. Room temperature polarization versus electric field measurements show a significant increase in the coercive field after the incorporation of CFO inside the PZT matrix. This work illustrates a simple, cost-effective synthesis technique that can be used to prepare nanocomposites of functional materials with desired room temperature functionalities and enhanced interfacial coupling between the two phases.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/283750

Magnetic mesoporous silica nanostructures: investigation of magnetic properties
NANOTECHNOLOGY
Autore/i: Talone, A.; Ruggiero, L.; Slimani, S.; Imperatori, P.; Barucca, G.; Ricci, M. A.; Sodo, A.; Peddis, D.
Classificazione: 1 Contributo su Rivista
Abstract: Magnetic mesoporous silica (MS) nanocomposites provide the possibility of generating multi-functional objects for application in different technological areas. This paper focuses on the magnetic properties of nanocomposites constituted by spinel iron oxide nanoparticles (magnetic nanoparticles (MNPs), < D > ≈ 8-9 nm) embedded in an MS matrix. The mesoporous structure of the silica matrix and the presence of the nanoparticles inside clearly emerge from transmission electron microscopy (TEM) measurements. Low temperature (5 K) field-dependent magnetization measurements reveal saturation magnetization (MS ) close to bulk value (M S bulk ∼ 90 emu g-1) for both MNPs and MNP/MS nanocomposites, indicating that the presence of silica does not affect the magnetic features of the single MNPs. Moreover, the dependence of the remanent magnetization on field (i.e. δM plots) at low temperature has shown a small but evident decrease of interaction in an MNP/MS sample with respect to MNP samples A m2 Kg-1. Finally, a partial orientation of the easy axis is observed when the MNPs are embedded in the silica matrix.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/283889

LaFeO3-CoFe2O4 bi-magnetic composite thin films prepared using an all-in-one synthesis technique
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
Autore/i: Sayed, F.; Kotnana, G.; Barucca, G.; Muscas, G.; Peddis, D.; Mathieu, R.; Sarkar, T.
Classificazione: 1 Contributo su Rivista
Abstract: Bi-phasic composite films are generally grown as multilayers that result in layer-by-layer morphology with each layer having a distinct chemical composition. In this work, we report an all-in-one chemical synthesis technique combined with spin-coating to prepare single-layer bi-magnetic LaFeO3 (LFO)-CoFe2O4 (CFO) composite thin films with both phases co-existing in the same layer. The films have been characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the magnetic properties have been probed using dc magnetometry at room and low temperature. The unique synthesis technique followed ensures homogeneity of the two phases on the nanoscale with grain sizes ~10 nm for CFO and few tens of nm for LFO, as observed from TEM images. XRD confirms the presence of only the desired LFO and CFO phases in the films without any undesired secondary phases. Magnetic hysteresis loops reveal a coercivity of ~0.2 T at room temperature that increases by nearly one order of magnitude at T = 5 K. The all-in-one synthesis technique reported here can be used to prepare different bi-phasic composites in the form of single-layer two-dimensional films as well as zero-dimensional nanoparticles by a suitable modification of the precursors, solvents, and chelating agents.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/275068

Development of a reliable method for contamination detection in raw metal powders for additive manufacturing
Euro PM 2018 Congress and Exhibition
Autore/i: Santecchia, E.; Mengucci, P.; Gatto, A.; Bassoli, E.; Denti, L.; Bondioli, F.; Barucca, G.
Editore: European Powder Metallurgy Association (EPMA)
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The evolution of additive manufacturing draws a growing attention to the quality of the raw materials involved. During Powder Bed Fusion (PBF), impurities can be trapped by the melting action of the laser or electron beam followed by a rapid solidification, resulting in discontinuities of the sintered products where failure is likely to start. To increase the quality of the sintered parts, it is mandatory to minimize the presence of impurities in the final product and therefore the risk of failure under service. This result can be achieved by improving the quality of the raw metal powders, which plays a key role in the overall process. In this study, intentionally contaminated AM metal powders were characterized by coupling scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques with a statistical treatment of the data, obtaining a reliable method for powder impurities detection.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/274891

Encapsulation of a neutral molecule into a cationic clay material: Structural insight and cytotoxicity of resveratrol/layered double hydroxide/BSA nanocomposites
NANOMATERIALS
Autore/i: Minnelli, C.; Laudadio, E.; Galeazzi, R.; Barucca, G.; Notarstefano, V.; Cantarini, M.; Armeni, T.; Mobbili, G.
Classificazione: 1 Contributo su Rivista
Abstract: Resveratrol (RES) is a stilbenoid polyphenol with interesting antitumor activity compromised by its poor solubility and bioavailability; thus, new approaches are necessary to improve its therapeutic effectiveness. In the present study, bovine serum albumin coated layered double hydroxide (LDH–BSA) was employed to encapsulate RES in order to overcome the above-mentioned usage limits. To evaluate the feasibility of neutral RES complexation with cationic LDH, we carried out molecular dynamics simulation in order to predict its structure and stability. In the supramolecular complex formed with LDH, RES disposes itself in the interlamellar region of LDH where it is stabilized by intermolecular interactions. The physico-chemical characteristics of the resulting nanocomplexes were studied by X-ray powder diraction, transmission electron microscopy, and attenuated total reflection Fourier transform infrared spectroscopy. The encapsulation efficiency and drug release studies were also performed. The combined experimental and computational approach were highly effective in giving insight into the interaction mode of the neutral RES with the charged LDH. Finally, the nanohybrid’s anticancer ability was evaluated in human lung cancer cell line (A549) resulting in higher activity with respect to bare RES. Overall, the results showed that the nanocomposites are suitable for biomedical applications as delivery agents of RES.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/273148

Graphite platelet films deposited by spray technique on low density polyethylene substrates
Materials Today: Proceedings
Autore/i: Di Bartolomeo, A.; Iemmo, L.; Urban, F.; Palomba, M.; Carotenuto, G.; Longo, A.; Sorrentino, A.; Giubileo, F.; Barucca, G.; Rovere, M.; Tagliaferro, A.; Ambrosone, G.; Coscia, U.
Editore: Elsevier Ltd
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: An inexpensive technique based on spraying a graphite lacquer on low-density polyethylene (LDPE) substrate has been proposed to produce large area thermoresistive films. Scanning electron microscopy analysis shows that the coatings are composed of overlapped graphite platelets. Raman measurements reveal that the deposited films are made of a good quality graphitic material. Electrical measurements as a function of temperature of graphite platelet films on LDPE have been carried out between-40 and +40°C and it has been found that the resistance of the films increases with increasing the temperature. This behaviour, opposite to that of graphite material, could be attributed to the thermal expansion effects of the substrate. Graphite platelet films deposited on LDPE are promising materials for thermoresistive applications in plastic electronics.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/276612

Symbiotic, low-temperature, and scalable synthesis of bi-magnetic complex oxide nanocomposites
NANOSCALE ADVANCES
Autore/i: Sayed, F.; Kotnana, G.; Muscas, G.; Locardi, F.; Comite, A.; Varvaro, G.; Peddis, D.; Barucca, G.; Mathieu, R.; Sarkar, T.
Classificazione: 1 Contributo su Rivista
Abstract: Functional oxide nanocomposites, where the individual components belong to the family of strongly correlated electron oxides, are an important class of materials, with potential applications in several areas such as spintronics and energy devices. For these materials to be technologically relevant, it is essential to design low-cost and scalable synthesis techniques. In this work, we report a low-temperature and scalable synthesis of prototypical bi-magnetic LaFeO3-CoFe2O4 nanocomposites using a unique sol-based synthesis route, where both the phases of the nanocomposite are formed during the same time. In this bottom-up approach, the heat of formation of one phase (CoFe2O4) allows the crystallization of the second phase (LaFeO3), and completely eliminates the need for conventional high-temperature annealing. A symbiotic effect is observed, as the second phase reduces grain growth of the first phase, thus yielding samples with lower particle sizes. Through thermogravimetric, structural, and morphological studies, we have confirmed the reaction mechanism. The magnetic properties of the bi-magnetic nanocomposites are studied, and reveal a distinct effect of the synthesis conditions on the coercivity of the particles. Our work presents a basic concept of significantly reducing the synthesis temperature of bi-phasic nanocomposites (and thus also the synthesis cost) by using one phase as nucleation sites for the second one, as well as using the heat of formation of one phase to crystallize the other.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/275303

Physics of matter: from the nanoscale structure to the macroscopic properties of materials
The First outstanding 50 years of "Università Politecnica delle Marche"
Autore/i: Albertini, G.; Barucca, G.; Francescangeli, O.; Lucchetta, D. E.; Lucchetti, L.; Mengucci, P.; Rinaldi, D.; Simoni, F.; Vita, F.
Editore: Springer
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/275117

Mechanism of magnetic heating in Mn-doped magnetite nanoparticles and the role of intertwined structural and magnetic properties
NANOSCALE
Autore/i: Del Bianco, L.; Spizzo, F.; Barucca, G.; Ruggiero, M. R.; Geninatti Crich, S.; Forzan, M.; Sieni, E.; Sgarbossa, P.
Classificazione: 1 Contributo su Rivista
Abstract: We study the mechanism of heat generation, induced by an alternating magnetic field, in magnetite nanoparticles doped with manganese, produced by thermal decomposition from organometallic precursors. We investigate a set of four samples obtained by varying the duration of the reflux treatment carried out at a temperature of 300 °C during the synthetic procedure. On increasing this parameter from 60 to 180 minutes, the mean size of the nanoparticles increases, though remaining below 10 nm, as well as the saturation magnetization, which in all the samples, thanks to the Mn doping, is higher than that in magnetite nanoparticles taken as a reference. The combination of these two events has two main consequences. First, it determines the intensity of dipolar interactions between the nanoparticles, thus influencing their magnetic relaxing behavior, which, in turn, is closely related to the heating efficiency. Secondly, in a heating test, it is possible to operate in the regime of non-linear magnetic response of the nanoparticles at values of amplitude and frequency of the alternating field usually employed for biomedical applications. We show that, in this regime, the Specific Absorption Rate (SAR) in each sample depends linearly on the fraction of nanoparticles that are not superparamagnetic. This opens the possibility of modulating the heating capacity of the produced nanoparticles, so as to match specific needs, changing only a single synthesis parameter and opportunely exploiting the strict connection between structural features, magnetic properties and measurement conditions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267644

Cross-contamination quantification in powders for additive manufacturing: A study on Ti-6Al-4V and maraging steel
MATERIALS
Autore/i: Santecchia, E.; Mengucci, P.; Gatto, A.; Bassoli, E.; Defanti, S.; Barucca, G.
Classificazione: 1 Contributo su Rivista
Abstract: Metal additive manufacturing is now taking the lead over traditional manufacturing techniques in applications such as aerospace and biomedicine, which are characterized by low production volumes and high levels of customization. While fulfilling these requirements is the strength of metal additive manufacturing, respecting the tight tolerances typical of the mentioned applications is a harder task to accomplish. Powder bed fusion (PBF) is a class of additive manufacturing in which layers of metal powder are fused on top of each other by a high-energy beam (laser or electron beam) according to a computer-aided design (CAD) model. The quality of raw powders for PBF affects the mechanical properties of additively manufactured parts strongly, and therefore it is crucial to avoid the presence of any source of contamination, particularly cross-contamination. In this study, the identification and quantification of cross-contamination in powders of Ti-6Al-4V and maraging steel was performed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) techniques. Experimental results showed an overall good reliability of the developed method, opening the way for applications in machine learning environments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269796

Powder Bed Fusion of Biomedical Co-Cr-Mo and Ti-6Al-4V Alloys: Microstructure and Mechanical Properties
Sustainable Materials Science and Technology II
Autore/i: Santecchia, Eleonora; Mengucci, Paolo; Gatto, Andrea; Bassoli, Elena; Denti, Lucia; Rutkowski, Bogdan; Czyrska-Filemonowicz, Aleksandra; Barucca, Gianni
Editore: Antonio Macias García, Eduardo Manuel Cuerda Correa and Joaquín R. Domínguez Vargas
Classificazione: 2 Contributo in Volume
Abstract: Powder bed fusion (PBF) is an additive manufacturing technique, which allows to build complex functional mechanical parts layer-by-layer, starting from a computer-aided design (CAD) model. PBF is particularly attractive for biomedical applications, where a high degree of individualization is required. In this work, the microstructure of two biomedical alloys, namely Co- Cr-Mo and Ti-6Al-4V, were studied by X-ray diffraction and electron microscopy techniques. Hardness and tensile tests were performed on the sintered parts.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/271130

Laser Powder Bed Fusion: tailoring the microstructure of alloys for biomedical applications
15th International Conferences and Exhibition on Nanosciences and Nanotechnologies (NN) / 11th International Symposium on Flexible Organic Electronics (ISFOE)
Autore/i: Santecchia, E; Mengucci, P; Gatto, A; Bassoli, E; Denti, L; Rutkowski, B; Barucca, G
Editore: ELSEVIER
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272088

Co/Pd-Based synthetic antiferromagnetic thin films on Au/resist underlayers: Towards biomedical applications
NANOSCALE
Autore/i: Varvaro, G.; Laureti, S.; Peddis, D.; Hassan, M.; Barucca, G.; Mengucci, P.; Gerardino, A.; Giovine, E.; Lik, O.; Nissen, D.; Albrecht, M.
Classificazione: 1 Contributo su Rivista
Abstract: Thin film stacks consisting of multiple repeats M of synthetic antiferromagnetic (SAF) [Co/Pd]N/Ru/[Co/Pd]N units with perpendicular magnetic anisotropy were explored as potential starting materials to fabricate free-standing micro/nanodisks, which represent a promising candidate system for theranostic applications. The films were directly grown on a sacrificial resist layer spin-coated on SiOx/Si(100) substrates, required for the preparation of free-standing disks after its dissolution. Furthermore, the film stack was sandwiched between two Au layers to allow further bio-functionalization. For M ≤ 5, the samples fulfill all the key criteria mandatory for biomedical applications, i.e., zero remanence, zero field susceptibility at small fields and sharp switching to saturation, together with the ability to vary the total magnetic moment at saturation by changing the number of repetitions of the multi-stack. Moreover, the samples show strong perpendicular magnetic anisotropy, which is required for applications relying on the transduction of a mechanical force through the micro/nano-disks under a magnetic field, such as the mechanical cell disruption, which is nowadays considered a promising alternative to the more investigated magnetic hyperthermia approach for cancer treatment. In a further step, SAF microdisks were prepared from the continuous multi-stacks by combining electron beam lithography and Ar ion milling, revealing similar magnetic properties as compared to the continuous films.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272498

Optimization of distances measurement by an ultrasonic sensor
15th International Conferences and Exhibition on Nanosciences and Nanotechnologies (NN) / 11th International Symposium on Flexible Organic Electronics (ISFOE)
Autore/i: Rocchi, A; Santecchia, E; Barucca, G; Mengucci, P
Editore: ELSEVIER
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272089

Glassy magnetic behavior and correlation length in nanogranular Fe-oxide and Au/Fe-oxide samples
MATERIALS
Autore/i: Del Bianco, L.; Spizzo, F.; Barucca, G.; Marangoni, G.; Sgarbossa, P.
Classificazione: 1 Contributo su Rivista
Abstract: In nanoscale magnetic systems, the possible coexistence of structural disorder and competing magnetic interactionsmay determine the appearance of a glassy magnetic behavior, implying the onset of a low-temperature disordered collective state of frozen magnetic moments. This phenomenology is the object of an intense research activity, stimulated by a fundamental scientific interest and by the need to clarify how disordered magnetism effects may affect the performance of magnetic devices (e.g., sensors and data storage media). We report the results of a magnetic study that aims to broaden the basic knowledge of glassy magnetic systems and concerns the comparison between two samples, prepared by a polyol method. The first can be described as a nanogranular spinel Fe-oxide phase composed of ultrafine nanocrystallites (size of the order of 1 nm); in the second, the Fe-oxide phase incorporated non-magnetic Au nanoparticles (10-20 nm in size). In both samples, the Fe-oxide phase exhibits a glassy magnetic behavior and the nanocrystallite moments undergo a very similar freezing process. However, in the frozen regime, the Au/Fe-oxide composite sample is magnetically softer. This effect is explained by considering that the Au nanoparticles constitute physical constraints that limit the length of magnetic correlation between the frozen Fe-oxide moments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272499

Quality Control and Structural Assessment of Anisotropic Scintillating Crystals
CRYSTALS
Autore/i: Montalto, Luigi; Natali, PIER PAOLO; Scalise, Lorenzo; Paone, Nicola; Davi', Fabrizio; Rinaldi, Daniele; Barucca, Gianni; Mengucci, Paolo
Classificazione: 1 Contributo su Rivista
Abstract: Nowadays, radiation detectors based on scintillating crystals are used in many different fields of science like medicine, aerospace, high energy physic and security. The scintillating crystals are the core elements of these devices; by converting high energy radiations in visible photons, they produce the optical signals to be detected and analyzed. Structural and surface conditions, defects and residual stress states play a crucial role in their operating performances like light production, transport and extraction. Industrial production of such crystalline materials is a complex process which requires sensing, in-line and off-line, for material characterization and process control to properly tune the production parameters. Indeed, scintillators quality must be accurately assessed during their manufacturing in order to prevent malfunction and failures at each level of the chain, optimizing the production and utilization costs. This paper presents an overview of the techniques used, at various stages, across the crystal production process, to assess quality and structural condition of anisotropic scintillating crystals. Different inspection techniques (XRD, SEM, EDX, TEM) and the non-invasive photoelasticity based methods for residual stress detection, such as Laser Conoscopy and Sphenoscopy, are presented. The use of XRD, SEM, EDX and TEM analytical methods offer detailed structural and morphological information. Conoscopy and Sphenoscopy offer the advantages of fast and non-invasive measurement methods suitable for the inspection of the whole crystal quality. These techniques, based on different measurement methods and models, provide different information which can be cross-correlated to obtain a complete characterization of the scintillating crystals. Inspection methods will be analyzed and compared in relation to present state of the art.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267755

Thermoresistive properties of graphite platelet films supported by different substrate
MATERIALS
Autore/i: Palomba, M.; Carotenuto, G.; Longo, A.; Sorrentino, A.; Di Bartolomeo, A.; Iemmo, L.; Urban, F.; Giubileo, F.; Barucca, G.; Rovere, M.; Tagliaferro, A.; Ambrosone, G.; Coscia, U.
Classificazione: 1 Contributo su Rivista
Abstract: Large-area graphitic films, produced by an advantageous technique based on spraying a graphite lacquer on glass and low-density polyethylene (LDPE) substrates were studied for their thermoresistive applications. The spray technique uniformly covered the surface of the substrate by graphite platelet (GP) unities, which have a tendency to align parallel to the interfacial plane. Transmission electron microscopy analysis showed that the deposited films were composed of overlapped graphite platelets of different thickness, ranging from a few tens to hundreds of graphene layers, and Raman measurements provided evidence for a good graphitic quality of the material. The GP films deposited on glass and LDPE substrates exhibited different thermoresistive properties during cooling-heating cycles in the -40 to +40 °C range. Indeed, negative values of the temperature coefficient of resistance, ranging from -4 × 10-4 to -7 × 10-4 °C-1 have been observed on glass substrates, while positive values varying between 4 × 10-3 and 8 × 10-3 °C-1 were measured when the films were supported by LDPE. These behaviors were attributed to the different thermal expansion coefficients of the substrates. The appreciable thermoresistive properties of the graphite platelet films on LDPE could be useful for plastic electronic applications.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/271997

Dipolar Magnetic Interactions in Mn-Doped Magnetite Nanoparticles Loaded into PLGA Nanocapsules for Nanomedicine Applications
JOURNAL OF PHYSICAL CHEMISTRY. C
Autore/i: Del Bianco, L.; Spizzo, F.; Sgarbossa, P.; Sieni, E.; Barucca, G.; Ruggiero, M. R.; Geninatti Crich, S.
Classificazione: 1 Contributo su Rivista
Abstract: Nanocapsules made of poly(lactic-co-glycolic acid) (PLGA) copolymer and with a different load of oleate-coated Mn-doped magnetite nanoparticles are studied for potential nanomedicine applications as nanocarriers with magnetic functionalities, in particular magnetic heating. The mean size of the PLGA nanocapsules and of the magnetic nanoparticles is around 200 and 8 nm, respectively. The aim is to study to what extent the different concentration of magnetic nanoparticles and their confinement into the PLGA nanocapsules affect their spatial arrangement and their magnetic interaction. This is crucial for making progress in the field of magnetic nanocarriers, tailoring their magnetic properties and thus optimizing their performance. The results obtained by combining structural and magnetic analyses indicate that the nanoparticles form aggregates into the PLGA nanocapsules - reaching larger dimension in the sample with the higher magnetic load - and that the dipolar interactions rule the magnetization process and the magnetic relaxing behavior, which are factors determining the magnetic heating capacity. In particular, a double role of the dipolar interactions in the magnetic heating mechanism is highlighted: they stabilize the magnetic moments of the nanoparticles against superparamagnetism and give rise to low-remanence magnetic configurations of the nanoparticle aggregates. While the first effect enhances the heating efficiency, the second one appears harmful
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272787

On the formation of nanocapsules in aerosol‐assisted atmospheric‐pressure plasma
PLASMA PROCESSES AND POLYMERS
Autore/i: Lo Porto, Chiara; Palumbo, Fabio; Fracassi, Francesco; Barucca, Gianni; Favia, Pietro
Classificazione: 1 Contributo su Rivista
Abstract: Aerosol-assisted atmospheric-pressure plasma can lead to the deposition of very appealing core-shell structured nanocapsules. In this work, the aerosol solution composition has been changed in terms of solute nature and concentration in order to better understand the nanocapsule formation and structure. In particular, electron microscopy techniques and microanalysis characterization have been carried out to provide a rationale for such one-step deposition of nanocapsules in plasma. A possible mechanism for the formation of the nanocapsules is suggested, based on the current theories on droplet evaporation in atomization processing, and on the implications of the coupling of aerosol with plasma environment.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269461

Solid-state phase transformations in thermally treated Ti-6Al-4V alloy fabricated via laser powder bed fusion
MATERIALS
Autore/i: Mengucci, P.; Santecchia, E.; Gatto, A.; Bassoli, E.; Sola, A.; Sciancalepore, C.; Rutkowski, B.; Barucca, G.
Classificazione: 1 Contributo su Rivista
Abstract: Laser Powder Bed Fusion (LPBF) technology was used to produce samples based on the Ti-6Al-4V alloy for biomedical applications. Solid-state phase transformations induced by thermal treatments were studied by neutron diffraction (ND), X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) and energy-dispersive spectroscopy (EDS). Although, ND analysis is rather uncommon in such studies, this technique allowed evidencing the presence of retained β in α' martensite of the as-produced (#AP) sample. The retained β was not detectable byXRDanalysis, nor by STEM observations. Martensite contains a high number of defects, mainly dislocations, that anneal during the thermal treatment. Element diffusion and partitioning are the main mechanisms in the α ↔ β transformation that causes lattice expansion during heating and determines the final shape and size of phases. The retained β phase plays a key role in the α' → β transformation kinetics.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/270246

Characterization and Optimization of Level Measurement by an Ultrasonic Sensor System
IEEE SENSORS JOURNAL
Autore/i: Rocchi, Andrea; Santecchia, Eleonora; Ciciulla, Fabrizio; Mengucci, Paolo; Barucca, Gianni
Classificazione: 1 Contributo su Rivista
Abstract: The problem of environmental disasters due to oil spills has characterized recent history from the early '900, still being an important risk factor for environmental protection. Aim of this research is designing and implementation of a non-contact ultrasonic sensor system capable of providing the water level in the marine environment. This system is part of a very low-cost device developed to detect water pollution by non-conductive liquids (i.e., hydrocarbons floating in the sea), exploiting the different conductivities of fluids involved. While equipment and techniques currently used for monitoring marine water pollution are very expensive, this paper focuses on the characterization of a low-cost SRF05 ultrasonic sensor and on its implementation inside a floating organ as a result of data obtained from laboratory tests. A number of experimental tests were conducted using a micrometric linear stage, a triangulation laser, a digital oscilloscope, and a post-processing software. Moreover, changes of climatic conditions, such as temperature and humidity, were monitored in a climatic chamber, aiming to establish the best operating range in terms of sensor resolution and the architecture of a buoy. The sensor showed signal anomalies at regular distance intervals due to anticipated flight times, which led to the adoption of a sensor system consisting in the combination of more SRF05 sensors to optimize the measurement system. In addition, it is presented an analytical method based on ultrasonic signal reconstruction, with the aim to improve the accuracy of the measurement method. The final device is managed to have a sensibility of about 1 mm.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264665

Enhancing the quality of metal powder feedstock for laser PBF through cross-contamination removal
Euro PM 2019 Congress and Exhibition
Autore/i: Santecchia, E.; Mengucci, P.; Gatto, A.; Bassoli, E.; Denti, L.; Gheorghiu, B.; Barucca, G.
Editore: European Powder Metallurgy Association (EPMA)
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The presence of impurities in metal powder feedstock for laser powder bed fusion (L-PBF) can strongly affect the mechanical properties of the sintered part. As a matter of fact, the contamination particles trapped in the uniform metal matrix of the raw material, act as a discontinuity and, therefore, as a site for fatigue crack nucleation and growth, leading to a dramatic reduction of the expected fatigue life. While cross-contamination detection is a key parameter to establish the quality level of the metal powder feedstock, its removal is crucial to ensure that the sintered parts will fulfil the service requirements. In this study, metal powder feedstock for laser PBF were intentionally contaminated, submitted to a removal process based on their magnetic properties, through suitably developed equipment. The contaminated and processed powders were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/288862

Precipitates formation and evolution in a Co-based alloy produced by powder bed fusion
JOURNAL OF ALLOYS AND COMPOUNDS
Autore/i: Santecchia, E.; Gatto, A.; Bassoli, E.; Denti, L.; Rutkowski, B.; Mengucci, P.; Barucca, G.
Classificazione: 1 Contributo su Rivista
Abstract: Metal additive manufacturing is strongly employed in aerospace and biomedical applications, whose high degree of customization and low production volumes are the main characteristics. Cobalt-based alloys have been widely used for dental prosthesis and can be produced via metal additive manufacturing, or rather powder bed fusion, in a more convenient way compared to traditional manufacturing techniques. In the present paper, a comprehensive study of the tight correlation between the microstructure and the static mechanical properties of Co-Cr-Mo-W samples produced by powder bed fusion, is reported. In particular, the formation of precipitates during the sintering process is observed, and the evolution of their size, shape and frequency due to post-processing and to a heat-treatment typical of dental applications, is exhaustively studied. By coupling different characterization techniques such as scanning transmission electron microscopy and small-angle neutron scattering, it was possible to correlate the ductility degradation of the samples with the formation and growth of coarse and elongated precipitates.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266706

Controlling magnetic coupling in bi-magnetic nanocomposites
NANOSCALE
Autore/i: Sayed, F.; Muscas, G.; Jovanovic, S.; Barucca, G.; Locardi, F.; Varvaro, G.; Peddis, D.; Mathieu, R.; Sarkar, T.
Classificazione: 1 Contributo su Rivista
Abstract: Magnetic nanocomposites constitute a vital class of technologically relevant materials, in particular for next-generation applications ranging from biomedicine, catalysis, and energy devices. Key to designing such materials is determining and controlling the extent of magnetic coupling in them. In this work, we show how the magnetic coupling in bi-magnetic nanocomposites can be controlled by the growth technique. Using four different synthesis strategies to prepare prototypical LaFeO3-CoFe2O4 and LaFeO3-Co0.5Zn0.5Fe2O4 nanocomposite systems, and by performing comprehensive magnetic measurements, we demonstrate that the final material exhibits striking differences in their magnetic coupling that is distinct to the growth method. Through structural and morphological studies, we confirm the link between the magnetic coupling and growth methods due to distinct levels of particle agglomeration at the very microscopic scale. Our studies reveal an inverse relationship between the strength of magnetic coupling and the degree of particle agglomeration in the nanocomposites. Our work presents a basic concept of controlling the particle agglomeration to tune magnetic coupling, relevant for designing advanced bi-magnetic nanocomposites for novel applications.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269815

The addition of silver affects the deformation mechanism of a twinning-induced plasticity steel: Potential for thinner degradable stents
ACTA BIOMATERIALIA
Autore/i: Loffredo, Sergio; Paternoster, Carlo; Giguère, Nicolas; Barucca, Gianni; Vedani, Maurizio; Mantovani, Diego
Classificazione: 1 Contributo su Rivista
Abstract: While Fe-based alloys have already been reported to possess all mechanical properties required for vascular stenting, their relatively low degradation rate in vivo still constitutes their main bottleneck. The inflammatory reaction generated by a stent is inversely proportional to its mass. Therefore, the tendency in stenting is to lower the section so to reduce the inflammatory reaction. Twinning-induced plasticity steels (TWIP) possess excellent mechanical properties for envisaging the next generation of thinner degradable cardiovascular stents. To accelerate the degradation, the addition of noble elements was proposed, aimed at promoting corrosion by galvanic coupling. In this context, silver was reported to generally increase the degradation rate. However, its impact on the deformation mechanism of TWIP steels has not been reported yet. Results show that the use of Ag significantly reduces the ductility without altering the strength of the material. Furthermore, the presence of Ag was found to promote a different deformation texture, thus stimulating the formation of mechanical martensite. Since a stent works in the deformed state, understanding the microstructure and texture resulting from plastic deformation can effectively help to forecast the degradation mechanisms taking place during implantation and the expected degradation time. Moreover, knowing the deformed microstructure allows to understand the formability of very small tubes, as precursors of the next generation of thin section degradable stents. Statement of significance: Commercial degradable magnesium stents are limited from their relatively big structure size. Twinning-induced plasticity steels possess outstanding mechanical properties, but their degradation time goes beyond the timeframe expected from clinics. The inclusion of noble Ag particles, which favor galvanic coupling, is known to promote corrosion and solve this limitation. However, it is necessary to understand the impact that Ag has on the deformation microstructure and on the mechanical properties. The addition of Ag reduces the ductility of a twinning-induced plasticity steel because of a different deformation microstructure. Since a stent works in a deformed state inside an artery, understanding the microstructural evolution after plastic deformation allows to better predict the device performances during service life.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265847

Encapsulation of vitamin B12 into nanoengineered capsules and soft matter nanosystems for targeted delivery
COLLOIDS AND SURFACES. B, BIOINTERFACES
Autore/i: Maiorova, L. A.; Erokhina, S. I.; Pisani, M.; Barucca, G.; Marcaccio, M.; Koifman, O. I.; Salnikov, D. S.; Gromova, O. A.; Astolfi, P.; Ricci, V.; Erokhin, V.
Classificazione: 1 Contributo su Rivista
Abstract: Targeted delivery of vitamins to a desirable area is an active branch in a modern pharmacology. The most important and difficult delivery of vitamin B12 is that to bone marrow and nerve cells. Herein we present a first step towards the development of two types of smart carriers, polymer capsules and lyotropic liquid-crystalline nanosystems, for vitamin B12 targeted delivery and induced release. A vitamin B12 encapsulation technique into nanoengineered polymeric capsules produced by layer-by-layer assembling of polymeric shells on CaCO3 templates has been developed. The effectiveness of the process was demonstrated by optical absorption spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and small-angle X-ray diffraction. TEM and AFM analyses performed on capsules after their drying, confirmed the presence of the vitamin B12 inside the capsules in the form of crystalline nanoaggregates, 50–300 nm in diameter. Soft lipid nanovectors consisting of amphiphilic phytantriol molecules, which in water excess spontaneously self-assembly in 3D wellordered inverse bicontinuous cubic bulk phase, were used as alternative carriers for vitamin B12. It was shown that about 30% of the vitamin added in the preparation of the soft lipid system was actually encapsulated in cubosomes and that no structural changes occurred upon loading. The Vitamin stabilizes the lipid system playing the role of its structure-forming element. The biocompatible nature, the stability and the feasibility of these systems make them good candidates as carriers for hydrophilic vitamins.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269787

Precision resonance energy scans with the PANDA experiment at FAIR
THE EUROPEAN PHYSICAL JOURNAL. A, HADRONS AND NUCLEI
Autore/i: Barucca, G; Davı, F; Lancioni, G; Mengucci, P; Montalto, L; Natali, P; Paone, N; Rinaldi, D; Scalise, L; Erni, W; Krusche, B; Steinacher, M; Walford, N; Cao, N; Liu, Z; Liu, C; Liu, B; Shen, X; Sun, S; Tao, J; Zhao, G; Zhao, J; Albrecht, M; Bökelmann, S; Erlen, T; Feldbauer, F; Fink, M; Frech, J; Freudenreich, V; Fritsch, M; Hagdorn, R; Heinsius, H; Held, T; Holtmann, T; Keshk, I; Koch, H; Kopf, B; Kuhlmann, M; Kümmel, M; Küßner, M; Leiber, S; Musiol, P; Mustafa, A; Pelizäus, M; Pitka, A; Reher, J; Reicherz, G; Richter, M; Schnier, C; Sersin, S; Sohl, L; Sowa, C; Steinke, M; Triffterer, T; Weber, T; Wiedner, U; Beck, R; Hammann, C; Hartmann, J; Ketzer, B; Müllers, J; Rossbach, M; Salisbury, B; Schmidt, C; Thoma, U; Urban, M; Bianconi, A; Bragadireanu, M; Pantea, D; Czyzycki, W; Domagala, M; Filo, G; Jaworowski, J; Krawczyk, M; Lisowski, E; Lisowski, F; Michałek, M; Płażek, J; Korcyl, K; Kozela, A; Kulessa, P; Lebiedowicz, P; Pysz, K; Schäfer, W; Szczurek, A; Fiutowski, T; Idzik, M; Swientek, K; Terlecki, P; Korcyl, G; Lalik, R; Malige, A; Moskal, P; Nowakowski, K; Przygoda, W; Rathod, N; Rudy, Z; Salabura, P; Smyrski, J; Augustin, I; Böhm, R; Lehmann, I; Nicmorus Marinescu, D; Schmitt, L; Varentsov, V; Al-Turany, M; Belias, A; Deppe, H; Dzhygadlo, R; Flemming, H; Gerhardt, A; Götzen, K; Heinz, A; Karabowicz, R; Kurilla, U; Lehmann, D; Lühning, J; Lynen, U; Nakhoul, S; Orth, H; Peters, K; Saito, T; Schepers, G; Schmidt, C J; Schwarz, C; Schwiening, J; Täschner, A; Traxler, M; Voss, B; Wieczorek, P; Abazov, V; Alexeev, G; Arefiev, V A; Astakhov, V; Barabanov, M Yu; Batyunya, B V; Dodokhov, V Kh; Fechtchenko, A; Galoyan, A; Golovanov, G; Koshurnikov, E K; Lobanov, Y Yu; Olshevskiy, A G; Piskun, A A; Samartsev, A; Shimanski, S; Skachkov, N B; Skachkova, A N; Strokovsky, E A; Tokmenin, V; Uzhinsky, V; Verkheev, A; Vodopianov, A; Zhuravlev, N I; Branford, D; Glazier, D; Watts, D; Böhm, M; Eyrich, W; Lehmann, A; Miehling, D; Pfaffinger, M; Stelter, S; Quin, N; Robison, L; Seth, K; Xiao, T; Bettoni, D; Ali, A; Hamdi, A; Krebs, M; Nerling, F; Belousov, A; Kisel, I; Kozlov, G; Pugach, M; Zyzak, M; Bianchi, N; Gianotti, P; Lucherini, V; Bracco, G; Bodenschatz, S; Brinkmann, K T; Diehl, S; Dormenev, V; Düren, M; Etzelmüller, E; Föhl, K; Galuska, M; Geßler, T; Gutz, E; Hahn, C; Hayrapetyan, A; Kesselkaul, M; Kühn, W; Lange, J S; Liang, Y; Metag, V; Moritz, M; Nanova, M; Novotny, R; Schmidt, M; Stenzel, H; Strickert, M; Thöring, U; Wasem, T; Wohlfahrt, B; Zaunick, H G; Tomasi-Gustafsson, E; Ireland, D; Seitz, B; Deepak, P N; Kulkarni, A; Apostolou, A; Kappert, R; Kavatsyuk, M; Loehner, H; Messchendorp, J; Rodin, V; Schakel, P; Vejdani, S; Dutta, K; Kalita, K; Sohlbach, H; Bianchi, L; Deermann, D; Derichs, A; Dosdall, R; Erven, A; Gillitzer, A; Goldenbaum, F; Grunwald, D; Jokhovets, L; Lai, A; Orfanitski, S; Prasuhn, D; Prencipe, E; Pütz, J; Ritman, J; Rosenthal, E; Schadmand, S; Schmitz, R; Sefzick, T; Serdyuk, V; Sterzenbach, G; Stockmanns, T; Wintz, P; Wüstner, P; Xu, H; Zhou, Y; Cao, X; Hu, Q; Li, H; Li, Z; Ma, X; Rigato, V; Isaksson, L; Achenbach, P; Aycock, A; Corell, O; Denig, A; Distler, M; Hoek, M; Lauth, W; Liu, Z; Merkel, H; Müller, U; Pochodzalla, J; Schlimme, S; Sfienti, C; Thiel, M; Zambrana, M; Ahmadi, H; Ahmed, S; Bleser, S; Bölting, M; Capozza, L; Dbeyssi, A; Grasemann, P; Klasen, R; Kliemt, R; Leithoff, H H; Maas, F; Maldaner, S; Michel, M; Morales Morales, C; Motzko, C; Noll, O; Pflüger, S; Rodríguez Piñeiro, D; Steinen, M; Wolff, S; Zimmermann, I; Fedorov, A; Korzhik, M; Missevitch, O; Balashoff, A; Boukharov, A; Malyshev, O; Balanutsa, P; Chernetsky, V; Demekhin, A; Dolgolenko, A; Fedorets, P; Gerasimov, A; Golubev, A; Goryachev, V; Kantsyrev, A; Kirin, D Y; Kotov, A; Kristi, N; Ladygina, E; Luschevskaya, E; Matveev, V A; Panjushkin, V; Stavinskiy, A V; Basant, K N; Jha, V; Kumawat, H; Mohanty, A K; Roy, B; Saxena, A; Yogesh, S; Bonaventura, D; Fritzsch, C; Grieser, S; Hargens, C; Hergemöller, A K; Hetz, B; Hüsken, N; Khoukaz, A; Wessels, J P; Herold, C; Khosonthongkee, K; Kobdaj, C; Limphirat, A; Nasawad, T; Simantathammakul, T; Srisawad, P; Yan, Y; Blinov, A E; Kononov, S; Kravchenko, E A; Antokhin, E; Barnyakov, M; Beloborodov, K; Blinov, V E; Kuyanov, I A; Pivovarov, S; Pyata, E; Tikhonov, Y; Kunne, R; Ramstein, B; Boca, G; Duda, D; Finger, M; Finger, M; Kveton, A; Pesek, M; Peskova, M; Prochazka, I; Slunecka, M; Gallus, P; Jary, V; Novy, J; Tomasek, M; Tomasek, L; Virius, M; Vrba, V; Abramov, V; Bukreeva, S; Chernichenko, S; Derevschikov, A; Ferapontov, V; Goncharenko, Y; Levin, A; Maslova, E; Melnik, Y; Meschanin, A; Minaev, N; Mochalov, V; Moiseev, V; Morozov, D; Nogach, L; Poslavskiy, S; Ryazantsev, A; Ryzhikov, S; Semenov, P; Shein, I; Uzunian, A; Vasiliev, A; Yakutin, A; Roy, U; Yabsley, B; Belostotski, S; Gavrilov, G; Izotov, A; Manaenkov, S; Miklukho, O; Veretennikov, D; Zhdanov, A; Makonyi, K; Preston, M; Tegner, P E; Wölbing, D; Atac, A; Bäck, T; Cederwall, B; Gandhi, K; Rai, A K; Godre, S; Calvo, D; De Remigis, P; Filippi, A; Mazza, G; Rivetti, A; Wheadon, R; Iazzi, F; Lavagno, A; Bussa, M P; Spataro, S; Martin, A; Akram, A; Calen, H; Ikegami Andersson, W; Johansson, T; Kupsc, A; Marciniewski, P; Papenbrock, M; Regina, J; Schönning, K; Wolke, M; Diaz, J; Pothodi Chackara, V; Chlopik, A; Kesik, G; Melnychuk, D; Trzcinski, A; Wojciechowski, M; Wronka, S; Zwieglinski, B; Amsler, C; Bühler, P; Kratochwil, N; Marton, J; Nalti, W; Steinschaden, D; Suzuki, K; Widmann, E; Zimmermann, S; Zmeskal, J
Classificazione: 1 Contributo su Rivista
Abstract: This paper summarises a comprehensive Monte Carlo simulation study for precision resonance energy scan measurements. Apart from the proof of principle for natural width and line shape measurements of very narrow resonances with PANDA, the achievable sensitivities are quantified for the concrete example of the charmonium-like X(3872) state discussed to be exotic, and for a larger parameter space of various assumed signal cross-sections, input widths and luminosity combinations. PANDA is the only experiment that will be able to perform precision resonance energy scans of such narrow states with quantum numbers of spin and parities that differ from {$} J^{{}PC{}} = 1^{{}--{}}{$}JPC=1--.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264613

Easy plasma nano-texturing of PTFE surface: From pyramid to unusual spherules-on-pyramid features
APPLIED SURFACE SCIENCE
Autore/i: Lo Porto, Chiara; Di Mundo, Rosa; Veronico, Valeria; Trizio, Ilaria; Barucca, Gianni; Palumbo, Fabio
Classificazione: 1 Contributo su Rivista
Abstract: Oxygen plasma etching of polytetrafluoroethylene has been investigated as a way to sculpture nano-features on its surface and producing a super-hydrophobic material in one step. It has been found that, depending on the experimental conditions, the shape of the structures engraved in the polymer surface passes from pyramidal to unique pyramids with well-defined spherules on the top. The latter are obtained without any mask/lithographic option. In a previous paper the water repellent character of such etched polytetrafluoroethylene surface has been well documented and explained by some of the authors. In this paper, instead, some insights in the formation mechanism of such unusual morphology are provided. Chemical and morphological characterization indicate in the iron surface contamination the clue for the formation of such complex agglomerates.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264870

Giant magneto-optical response in H+ irradiated Zn1−xCoxO thin films
JOURNAL OF MATERIALS CHEMISTRY. C
Autore/i: Varvaro, G.; Di Trolio, A.; Polimeni, A.; Gabbani, A.; Pineider, F.; De Julián Fernández, C.; Barucca, G.; Mengucci, P.; Amore Bonapasta, A.; Testa, A. M.
Classificazione: 1 Contributo su Rivista
Abstract: Remarkable improvements in the magneto-optical properties of Zn1xCoxO thin films were achieved by post-growth hydrogen irradiation at temperatures of 400 1C. Hydrogen incorporation increases the magnetic circular dichroism signal resulting in large values of ellipticity and Faraday rotation at room temperature. The hysteretic behavior of the magneto-optical field dependent loops at different subbandgap wavelengths indicates an intrinsic ferromagnetic regime. A giant Faraday rotation of 3000 deg cm1 was observed at 400 nm. Optical, structural and microstructural characterizations pointed out the Zn substitution by Co, ruling out the presence of noticeable Co-related secondary phases down to the nanoscale. The increased values of saturation magnetization, ellipticity and Faraday rotation have been explained based on an impurity band close to the conduction band minimum, which is induced by Co–VO (O vacancies) complexes. A phenomenological model founded on such an impurity band and electronic states induced by other Co-defect complexes in the ZnO energy gap allows a thoroughly novel, fine interpretation of the ellipticity spectra.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264281

Surface modification of L605 by oxygen plasma immersion ion implantation for biomedical applications
MRS COMMUNICATIONS
Autore/i: De Andrade, L. M.; Paternoster, C.; Montaño-Machado, V.; Barucca, G.; Sikora-Jasinska, M.; Tolouei, R.; Turgeon, S.; Mantovani, D.
Classificazione: 1 Contributo su Rivista
Abstract: Co-Cr alloys, more specifically L605, have superior mechanical properties and high-corrosion resistance, making them suitable materials for cardiovascular application. However, metallic materials for biomedical applications require finely tuned surface properties to improve the material behavior in a physiological environment. Oxygen plasma immersion ion implantation was performed on an L605 alloy, after an electropolishing pre-treatment. The oxidized layer was found to be rich in Co and O, it did not show any trace of Cr, and resulted in nanostructured. The corrosion properties were profoundly changed. Endothelial cells showed high viability after 7 days of contact with some modified surfaces.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/261544

L10-FeNi films on Au-Cu-Ni buffer-layer: a high-throughput combinatorial study
SCIENTIFIC REPORTS
Autore/i: Giannopoulos, G.; Barucca, G.; Kaidatzis, A.; Psycharis, V.; Salikhov, R.; Farle, M.; Koutsouflakis, E.; Niarchos, D.; Mehta, A.; Scuderi, M.; Nicotra, G.; Spinella, C.; Laureti, S.; Varvaro, G.
Classificazione: 1 Contributo su Rivista
Abstract: The fct L10-FeNi alloy is a promising candidate for the development of high performance criticalelements- free magnetic materials. Among the different materials, the Au-Cu-Ni alloy has resulted very promising; however, a detailed investigation of the effect of the buffer-layer composition on the formation of the hard FeNi phase is still missing. To accelerate the search of the best Au-Cu-Ni composition, a combinatorial approach based on High-Throughput (HT) experimental methods has been exploited in this paper. HT magnetic characterization methods revealed the presence of a hard magnetic phase with an out-of-plane easy-axis, whose coercivity increases from 0.49 kOe up to 1.30 kOe as the Au content of the Cu-Au-Ni buffer-layer decreases. Similarly, the out-of-plane magnetocrystalline anisotropy energy density increases from 0.12 to 0.35 MJ/m3. This anisotropy is attributed to the partial formation of the L10 FeNi phase induced by the buffer-layer. In the range of compositions we investigated, the buffer-layer structure does not change significantly and the modulation of the magnetic properties with the Au content in the combinatorial layer is mainly related to the different nature and extent of interlayer diffusion processes, which have a great impact on the formation and order degree of the L10 FeNi phase.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264274

Optical and electrical characterizations of graphene nanoplatelet coatings on low density polyethylene
JOURNAL OF VACUUM SCIENCE AND TECHNOLOGY. B, NANOTECHNOLOGY & MICROELECTRONICS
Autore/i: Palomba, Mariano; Longo, Angela; Carotenuto, Gianfranco; Coscia, Ubaldo; Ambrosone, Giuseppina; Rusciano, Giulia; Nenna, Giuseppe; Barucca, Gianni; Longobardo, Luigi
Classificazione: 1 Contributo su Rivista
Abstract: Coatings of graphene nanoplatelets (GNPs) were deposited on a low density polyethylene (LDPE) substrate by a micromechanical method based on rubbing graphite platelets against the surface of the polymer. Transmission electron microscopy measurements reveal that the coatings were composed of nanoplatelets containing 13–30 graphene layers. Thermal gravimetric analysis shows that the investigated GNP coatings on LDPE (GNP/LDPE) samples are thermally stable up to 250 C. Optical spectra of these samples, compared to those of pristine LDPE in the ultravioletvisible- near-infrared range, indicate an increase in both reflectance and absorptance. On the other hand, the coating is able to markedly improve the surface conductivity of the polymeric substrate, indeed in the case of electrical contacts in the coplanar configuration (1 cm long and spaced 1mm), the resistance of LDPE is 1015X, while that of GNP/LDPE is 670X. Electrical measurements under white light illumination point out a decrease in the conductance and a linear behavior of the photoconductance as a function of the optical power density. GNP/LDPE materials can be used for their optical, electrical, thermal, and flexibility properties in large area plastic electronics and optoelectronics.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251875

Zn nanoparticle formation in FIB irradiated single crystal ZnO
APPLIED SURFACE SCIENCE
Autore/i: Pea, M.; Barucca, Gianni; Notargiacomo, A.; Di Gaspare, L.; Mussi, V.
Classificazione: 1 Contributo su Rivista
Abstract: We report on the formation of Zn nanoparticles induced by Ga+ focused ion beam on single crystal ZnO. The irradiated materials have been studied as a function of the ion dose by means of atomic force microscopy, scanning electron microscopy, Raman spectroscopy and transmission electron microscopy, evidencing the presence of Zn nanoparticles with size of the order of 5–30 nm. The nanoparticles are found to be embedded in a shallow amorphous ZnO matrix few tens of nanometers thick. Results reveal that ion beam induced Zn clustering occurs producing crystalline particles with the same hexagonal lattice and orientation of the substrate, and could explain the alteration of optical and electrical properties found for FIB fabricated and processed ZnO based devices
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251685

Tunable single-phase magnetic behavior in chemically synthesized AFeO3-MFe2O4 (A = Bi or La, M = Co or Ni) nanocomposites
NANOSCALE
Autore/i: Sarkar, T.; Muscas, G.; Barucca, G.; Locardi, F.; Varvaro, G.; Peddis, D.; Mathieu, R.
Classificazione: 1 Contributo su Rivista
Abstract: The properties of magnetic nanocomposites rely strongly on the interplay between those of the constituent components. When the individual components themselves are complex systems belonging to the family of correlated electron oxide systems which typically exhibit exotic physical properties, it becomes nontrivial to customize the properties of the nanocomposite. In this paper, we demonstrate an easy, but effective method to synthesize and tune the magnetic properties of nanocomposites consisting of correlated electron oxide systems as the individual components. Our method is based on a novel synthesis technique by which the two components of the nanocomposite can be directly integrated with each other, yielding homogeneous samples on the nanoscale with magnetic behavior reminiscent of a single phase. We illustrate our method using multiferroic BiFeO3 (BFO) and LaFeO3 (LFO) as the major phase (i.e., matrix), and MFe2O4 (M = Co2+ or Ni2+) as the embedded magnetic phase. Furthermore, we show that by a proper selection of the second phase in the nanocomposite, it is possible to customize the magnetic properties of the matrix. We illustrate this by choosing CoFe2O4 and NiFe2O4, two oxides with widely differing magnetic anisotropies, as the embedded phase, and demonstrate that the coercivity of BFO and LFO can be increased or decreased depending on the choice of the embedded phase in the nanocomposite.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264277

Magnetic anisotropy phase-graded A1/L10-FePt films on amorphous glass substrates
Proceedings of Intermag Europe 2017
Autore/i: Barucca, Gianni; Speliotis, T. H.; Giannopoulos, G.; Niarchos, D.; Rutkowski, B.; Czyrska Filemonowicz, A.; Agostinelli, E.; Laureti, S.; Testa, A. M.; Varvaro, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251547

Direct metal laser sintering of biomedical Co-Cr-Mo and Ti-6Al-4V alloys: microstructure and mechanical properties.
Abstract book 2nd International Conference on Sustainable Materials Science and Technology (SMST”), 19-21 July, Canary Islands (SPAIN)
Autore/i: Barucca, G.; Mengucci, P.; Gatto, A.; Bassoli, E.; Denti, L.; Rutkowski, B.; Czyrska-Filemonowicz, A.; Fiori, F.; Girardin, E.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/263111

Magnetic anisotropy phase-graded A1/L10-FePt films on amorphous glass substrates
MATERIALS & DESIGN
Autore/i: Barucca, Gianni; Speliotis, T. h.; Giannopoulos, G.; Niarchos, D.; Rutkowski, B.; Czyrska Filemonowicz, A.; Agostinelli, E.; Laureti, S.; Testa, A. M.; Varvaro, G.
Classificazione: 1 Contributo su Rivista
Abstract: Magnetic anisotropy phase-graded A1/L10-FePt films deposited on amorphous glass substrates were investigated combining ultra-high resolution electron microscopy and angular-dependent magnetic measurements. A highly textured (001) L10 FePt film was first deposited at the relative low temperature of 625 K using an MgO/Cr underlayer stack, hence a second layer was grown while continuously decreasing the deposition temperature down to a final value ranging from 515 K to 365 K depending on the layer thickness (tg). This procedure leaded to the formation of a phase-graded system consisting of hard and soft magnetic phases separated by a rough nanometer-size interphase boundary, where the magnetic anisotropy gradually changes due to the variation of the relative amount of hard and soft phases across the whole film thickness. Electron microscopy analysis allowed the structure of the samples to be investigated at an atomic level. The A1 and L10-FePt phases were localized inside the film and the orientation relationships between their lattices were determined. The samples show a preferential perpendicular anisotropy up to tg = 15 nm and a significant reduction of the coercive field with the increase of the graded layer thickness (~ 30% for tg = 5 nm), suggesting their potential application as magnetic recording media.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/246496

The effect of microstructure on magnetic coupling in FePt/spacer/FePt trilayers
Abstract book of EUROMAT 2017
Autore/i: Kaidatzis, A.; Giannopoulos, G.; Psycharis, V.; Niarchos, D.; Barucca, Gianni; Dimitrakopulos, G. P.; Karakostas, T. H.; Komninou, P. H.; José Miguel García, Martín; Varvaro, G.; Testa, A. M.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251548

Investigation of magnetic coupling in FePt/spacer/FePt trilayers
JOURNAL OF PHYSICS D. APPLIED PHYSICS
Autore/i: Kaidatzis, A; Giannopoulos, G; Varvaro, G; Dimitrakopulos, G; Psycharis, V; Garcia Martin, J. M; Testa, A. M; Barucca, Gianni; Karakostas, T; Komninou, P; Niarchos, D.
Classificazione: 1 Contributo su Rivista
Abstract: The effect of different spacer materials (MgO, W, and Pt) on the magnetic coupling in FePt/ spacer/FePt trilayers has been carefully investigated. MgO results in magnetically coupled FePt layers with perpendicular magnetic anisotropy (PMA); W gives rise to a magnetically coupled system consisting of layers with PMA and in-plane magnetic anisotropy whereas Pt results in magnetically decoupled FePt layers with PMA. The trilayer microstructure is essential for explaining the obtained results. The growth mode of the top FePt layer is strongly affected by the underlying non-magnetic spacer, with occurrence of different morphologies; in particular, L10 FePt islands grow on MgO, a continuous FePt layer with fcc crystal structure is obtained on W, whereas a continuous layer with L10 structure is observed when the top layer is deposited on Pt.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251551

Magnetically decoupled L10 FePt/spacer/L10 FePt trilayers for 3D magnetic recording
Proceedings Intermag Europe 2017
Autore/i: Kaidatzis, A.; Giannopoulos, G.; Psycharis, V.; Niarchos, D.; José Miguel García, Martín; Varvaro, G.; Testa, A. M.; Barucca, Gianni; Dimitrakopoulos, G.; Karakostas, T.; Komninou, P.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251546

Modifications of single-crystal ZnO properties induced by FIB fabrication
Abstract book of Nanopatterning 2017 Conference: Nanoscale Pattern Formation at Surfaces
Autore/i: Pea, M.; Notargiacomo, A.; Barucca, Gianni; Stumpf, F.; Rommel, M.; Di Gaspare, L.; Mussi, V.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251550

Formation of metallic Zn nanoparticles by FIB irradiation of single crystal ZnO
Abstract book of International Conference on Micro and Nano Engineering-MNE 2017
Autore/i: Pea, M.; Barucca, Gianni; Notargiacomo, A.; Stumpf, F.; Rommel, M.; Di Gapare, L.; Mussi, V.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251549

Effects of build orientation and element partitioning on microstructure and mechanical properties of biomedical Ti-6Al-4V alloy produced by laser sintering
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
Autore/i: Mengucci, Paolo; Gatto, A.; Bassoli, E.; Denti, L.; Fiori, Fabrizio; Girardin, Emmanuelle; Bastianoni, Piergiorgio; Rutkowski, B.; Czyrska Filemonowicz, A.; Barucca, Gianni
Classificazione: 1 Contributo su Rivista
Abstract: Direct Metal Laser Sintering (DMLS) technology was used to produce tensile and flexural samples based on the Ti-6Al-4V biomedical composition. Tensile samples were produced in three different orientations in order to investigate the effect of building direction on the mechanical behavior. On the other hand, flexural samples were submitted to thermal treatments to simulate the firing cycle commonly used to veneer metallic devices with ceramics in dental applications. Roughness and hardness measurements as well as tensile and flexural mechanical tests were performed to study the mechanical response of the alloy while X-ray diffraction (XRD), electron microscopy (SEM, TEM, STEM) techniques and microanalysis (EDX) were used to investigate sample microstructure. Results evidenced a difference in the mechanical response of tensile samples built in orthogonal directions. In terms of microstructure, samples not submitted to the firing cycle show a single phase acicular α’ (hcp) structure typical of metal parts subject to high cooling rates. After the firing cycle, samples show a reduction of hardness and strength due to the formation of laths of the β (bcc) phase at the boundaries of the primary formed α’ plates as well as to lattice parameters variation of the hcp phase. Element partitioning during the firing cycle gives rise to high concentration of V atoms (up to 20 wt%) at the plate boundaries where the β phase preferentially forms.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/239995

A new micromechanical approach for the preparation of graphene nanoplatelets deposited on polyethylene
NANOTECHNOLOGY
Autore/i: Coscia, U.; Palomba, M.; Ambrosone, G.; Barucca, Gianni; Cabibbo, Marcello; Mengucci, Paolo; De Asmundis, R.; Carotenuto, G.
Classificazione: 1 Contributo su Rivista
Abstract: An advantageous micromechanical technique to deposit large area graphene nanoplatelet (GNP) thin films on a low-density polyethylene substrate is proposed. This method is based on the application of shear-stress and friction forces to a graphite platelets/ethanol paste on the surface of a polymeric substrate; it allows us to obtain a continuous film of superimposed nanoplatelets mainly made of 13–30 graphene layers. X-ray diffraction (XRD), atomic force and transmission electron microscopy (TEM) measurements support the occurrence of a partial exfoliation of the graphite platelets due to shear-stress and friction forces applied during film formation. Scanning electron microscopy (SEM) observations point out that the surface of the polymer is uniformly coated by the overlap of GNPs, and TEM analysis reveals the tendency of the nanoplatelets to align parallel to the interface plane. It has been found that the deposited samples, under white light illumination, exhibit a negative photoconductivity and a linear photoresponse as a function of the applied voltage and the optical power density in the −120÷120 mV and 20.9÷286.2 mWcm−2 ranges, respectively.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/246670

Ledge-type Co/L10-FePt exchange-coupled composites
JOURNAL OF APPLIED PHYSICS
Autore/i: Speliotis, T. h.; Giannopoulos, G.; Niarchos, D.; Li, W. F.; Hadjipanayis, G.; Barucca, Gianni; Agostinelli, E.; Laureti, S.; Peddis, D.; Testa, A. M.; Varvaro, G.
Classificazione: 1 Contributo su Rivista
Abstract: FePt-based exchange-coupled composites consisting of a magnetically hard L10-FePt phase exchange-coupled with a soft ferromagnetic material are promising candidates for future ultra-high density (>1 Tbit/in2) perpendicular magnetic recording media, also being of interest for other applications including spin torque oscillators and micro-electro-mechanical systems, among others. In this paper, the effect of the thickness of a soft Co layer (3 < thCo < 20 nm) on the magnetic behavior of ledge-type fcc(100)-Co/L10(001)-FePt composites deposited on an MgO (100) substrate is systematically studied by combining morpho-structural analyses and angular magnetization measurements. Starting from a film consisting of isolated L10(001)-FePt islands, the ledge-type structure was obtained by depositing a Co layer that either covered the FePt islands or filled-up the inter-island region, gradually forming a continuous layer with increasing Co thickness. A perpendicular anisotropy was maintained up to thCo ∼ 9.5 nm and a significant reduction in the coercivity (about 50% for thCo ∼ 3 nm) with the increase in thCo was observed, indicating that, by coupling hard FePt and soft Co phases in a ledge-type configuration, the writability can be greatly improved. Recoil loops' measurements confirmed the exchange-coupled behavior, reinforcing a potential interest in these systems for future magnetic recording media.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/237688

Structural and electrical characterizations of polymer-supported graphene fabricated by graphite nanoplatelets
IET Conference Publications
Autore/i: Coscia, U.; Palomba, M.; Ambrosone, G.; Barucca, Gianni; Carotenuto, G.
Editore: Institution of Engineering and Technology
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/250813

Oxygen plasma immersion ion implanted of L605 Co-Cr alloy for biomedical applications
Abstracts book of 2016 MRS Spring Meeting
Autore/i: Carlo, Paternoster; Letícia Marin De, Andrade; Vanessa Montaño, Machado; Cabibbo, Marcello; Barucca, Gianni; Nora, Lecis; Stéphane, Turgeon; Diego, Mantovani
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251542

Exchange bias properties of 140nm-sized dipolarly interacting circular dots with ultrafine IrMn and NiFe layers
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
Autore/i: Spizzo, F; Tamisari, M.; Chinni, F.; Bonfiglioli, E.; Gerardino, A.; Barucca, Gianni; Bisero, D.; Fin, S.; Del Bianco, L.
Classificazione: 1 Contributo su Rivista
Abstract: Westudied the exchange bias effect in an array of IrMn(3nm)/NiFe(3nm) circular dots (size 140nm and center-to-centerdistance 200nm, as revealed by microscopy analyses), prepared on a large area (33 mm2) by electron beam lithography and lift-off, using dc sputtering deposition. Hysteresis loops were measured by SQUID magnetometer at increasing values of temperature T (in the5–300Krange) after cooling from 300K down to 5K in zero field (ZFC mode) and in a saturating magnetic field (FC mode). The exchange bias effect disappears above T200K and, at each temperature,the exchange field HEX measured in ZFC is substantially lower than the FC one. Micromagnetic calculations indicate that, at room temperature, each dot is in high-remanence ground state, but magnetic dipolar interactions establish alow remanence configuration of the array as a whole. Hence, at low temperature, following the ZFC procedure, the exchange anisotropy in the dot array is averaged out, tending to zero. However,even the FC values of HEX and of the coercivity HC are definitely smaller compared to those measured in a reference continuous film with the same stack configuration (at T=5 K, HEX 90 Oe and HC 180Oe in the dots and HEX1270Oe and HC860 Oe in the film). Our explanation is based on the proven glassy magnetic nature of the ultrathin IrMn layer, implying the existence of magnetic correlations among the spins, culminating in a collective freezing below T100K. We propose, also by the light of micromagnetic simulations, that the small dot size imposes a spatial constraint on the magnetic correlation length among the IrMn spins so that, even at the lowest temperature, their thermal stability, especially at the dot border, is compromised.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/229118

Idrogel nanocomposito per radioterapia oncologica
Autore/i: Barucca, Gianni; Del Bianco, Lucia
Classificazione: 6 Brevetti
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/276598

Structural and magnetic properties of L10 FePt / MgO, W, Pt / L10 FePt trilayers
Abstract book of of 61ST ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS
Autore/i: Giannopoulos, G.; Kaidatzis, A.; Psycharis, V.; Niarchos, D.; Garcia martin, J.; Varvaro, G.; Testa, A.; Barucca, Gianni
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251545

Structural and mechanical characterization of Cr-Co alloy after oxygen plasma immersion ion implantion
Conference Abstract: 10th World Biomaterials Congress
Autore/i: Marin De Andrade, L; Paternoster, C; Cabibbo, Marcello; Barucca, Gianni; Lecis, N; Mostaed, E; Vedani, M; Turgeon, S; Mantovani, D.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251544

Biomedical Co-Cr-Mo Components Produced by Direct Metal Laser Sintering
Materials Today: Proceedings
Autore/i: Girardin, Emmanuelle; Barucca, Gianni; Mengucci, Paolo; Fiori, Fabrizio; Bassoli, E.; Gatto, A.; Iuliano, L.; Rutkowski, B.
Editore: ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Direct Metal Laser Sintering (DMLS) is an additive manufacturing technique based on a laser power source that sinters powdered materials using a 3D CAD model. The mechanical components produced by this procedure typically show higher residual porosity and poorer mechanical properties than those obtained by traditional manufacturing techniques. In this study, samples were produced by DMLS starting from a Co-Cr-Mo powder (in the γ phase) with a composition suitable for biomedical applications. Samples were submitted to hardness measurements and structural characterization. The samples showed a hardness value remarkably higher that those commonly obtained for the same cast or wrought alloys. In fact, the HRC value measured for the samples is 47 HRC, while the usual range for CAST Co-Cr-Mo is from 25 to 35 HRC. The samples microstructure was investigated by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and energy dispersive microanalysis (EDX) in order to clarify the origin of this unexpected result. The laser treatment induced a melting of the metallic Co-Cr-Mo powder, generating a phase transformation from the γ (fcc) to the ɛ (hcp) phase. The rapid cooling of the melted powder produced the formation of ɛ (hcp) nano-lamellae inside the γ (fcc) phase. The nano-lamellae formed an intricate network responsible for the measured hardness increase. The results suggest possible innovative applications of the DMLS technique to the production of mechanical parts in the medical and dental fields, where a high degree of personalization is required.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235710

Focused ion beam surface treatments of single crystal zinc oxide for device fabrication
MATERIALS & DESIGN
Autore/i: Pea, M.; Mussi, V.; Barucca, Gianni; Giovine, E.; Rinaldi, A.; Araneo, R.; Notargiacomo, A.
Classificazione: 1 Contributo su Rivista
Abstract: We investigated 30 kV Ga+ ions treatments on (0001) single crystal ZnO in order to assess the potentiality of ion beam based device fabrication on such material. A multi-technique approach combining atomic force microscopy, Raman and energy dispersive X-Ray spectroscopies, and transmission electron microscopy was used to study morphological and structural properties of ZnO upon varying the ion dose. At low doses a shallow defective layer develops showing an increasing defect density as the dose is increased. At higher dose a thinner defective layer with an amorphous layer on top is produced. The ion beam damaged layer on high resistivity ZnO shows enhanced conductivity. KOH based etching removed selectively the damaged ZnO and was found to dissolve rapidly the Ga-rich amorphous layer. The defective layer has an etch rate which depends on the ion dose, and even for prolonged etching processes it was not completely removed. However, conductivity measurements on ion beam fabricated pillars showed that the residual defects do not give a detectable electrical response. These findings indicate that electronic devices and micro-structures with pristine electrical properties of the ZnO crystal can be reliably fabricated by focused ion beam, provided the damaged surface layer is removed by proper etching procedures.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/238691

Designing new ferrite/manganite nanocomposites
NANOSCALE
Autore/i: Muscas, G.; Anil Kumar, P.; Barucca, Gianni; Concas, G.; Varvaro, G.; Mathieu, R; Peddis, D.
Classificazione: 1 Contributo su Rivista
Abstract: Two kinds of nanocomposites of transition metal oxides were synthesized and investigated. Each nanocomposite comprises nanoparticles of La0.67Ca0.33MnO3 and CoFe2O4 in similar volume fractions, however arranged with different morphologies. The temperature-dependent magnetic and electrical properties of the two systems are found to greatly differ, suggesting different degrees of interaction and coupling of their constituents. This is confirmed by magnetic field-dependent experiments, which reveal contrasted magnetization reversal and magnetoresistance in the systems. We discuss this morphology–physical property relationship, and the possibility to further tune the magnetism and magneto-transport in such nanocomposites.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/233897

Effects of thermal treatments on microstructure and mechanical properties of a Co-Cr-Mo-W biomedical alloy produced by laser sintering
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
Autore/i: Mengucci, Paolo; Barucca, Gianni; Gatto, A.; Bassoli, E.; Denti, L.; Fiori, Fabrizio; Girardin, Emmanuelle; Bastianoni, Piergiorgio; Rutkowski, B.; Czyrska Filemonowicz, A.
Classificazione: 1 Contributo su Rivista
Abstract: Direct Metal Laser Sintering (DMLS) technology based on a layer by layer production process was used to produce a Co-Cr-Mo-W alloy specifically developed for biomedical applications. The alloy mechanical response and microstructure were investigated in the as-sintered state and after post-production thermal treatments. Roughness and hardness measurements, and tensile and flexural tests were performed to study the mechanical response of the alloy while X-ray diffraction (XRD), electron microscopy (SEM, TEM, STEM) techniques and microanalysis (EDX) were used to investigate the microstructure in different conditions. Results showed an intricate network of -Co (hcp) lamellae in the γ-Co (fcc) matrix responsible of the high UTS and hardness values in the as-sintered state. Thermal treatments increase volume fraction of the -Co (hcp) martensite but slightly modify the average size of the lamellar structure. Nevertheless, thermal treatments are capable of producing a sensible increase in UTS and hardness and a strong reduction in ductility. These latter effects were mainly attributed to the massive precipitation of an hcp Co3(Mo,W)2Si phase and the contemporary formation of Si-rich inclusions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/233357

Ledge-type Co/L10-FePt exchange-coupled composites
Proceedings of ICM-2015, Barcelona (ES)
Autore/i: Speliotis, T. H.; Giannopoulos, G.; Niarchos, D.; Li, W. F.; Hadjipanayis, G.; Barucca, Gianni; Agostinelli, E.; Fiorani, D.; Laureti, S.; Peddis, D.; Testa, A. M.; Varvaro, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251534

Biomedical Co-Cr-Mo Components Produced by Direct Metal Laser Sintering
Conference Book for COST MP1005 - International Conference on Unified Scientific Approaches towards Regenerative Dentistry and Orthopaedics - REDEOR
Autore/i: Barucca, Gianni; Girardin, Emmanuelle; Mengucci, Paolo; Fiori, Fabrizio; Bassoli, E.; Gatto, A.; Iuliano, L.; Rutkowski, B.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251539

Magnetic exchange coupling in IrMn/NiFe nanostructures: From the continuous film to dot arrays.
PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS
Autore/i: F., Spizzo; E., Bonfiglioli; M., Tamisari; A., Gerardino; Barucca, Gianni; A., Notargiacomo; F., Chinni; L., Del Bianco
Classificazione: 1 Contributo su Rivista
Abstract: A comprehensive description of the exchange bias phenomenon in an antiferromagnetic/ferromagnetic IrMn(10 nm)/NiFe(5 nm) continuous film and in arrays of square dots with different sizes (1000, 500, and 300 nm) is presented, which elucidates the temperature dependence of the exchange field Hex and coercivity HC, in conjunction with spatial confinement effects. To achieve this goal, samples prepared by electron beam lithography and lift-off using dc sputtering were subjected to structural investigations by electron microscopy techniques and to magnetic study, through SQUID and magneto-optic magnetometry measurements coupled to micromagnetic calculations. In particular, we have observed that at T=300K Hex decreases by reducing the size of the dots and it is absent in the smallest ones, whereas the opposite trend is visible at T=10K (Hex∼1140Oe in the dots of 300nm). The exchange bias mechanism and its thermal evolution have been explained through an exhaustive phenomenological model, which joins spatial confinement effects with other crucial items concerning the pinning antiferromagnetic phase: the magnetothermal stability of the nanograins forming the IrMn layer (mean size ∼10nm), assumed as essentially noninteracting from the magnetic point of view; the proven existence of a structurally disordered IrMn region at the interface between the NiFe phase and the bulk of the IrMn layer, with a magnetic glassy nature; and the stabilization of a low-temperature (T<100K) frozen collective regime of the IrMn interfacial spins, implying the appearance of a length of magnetic correlation among them.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/221917

Biomedical metal alloys produced by direct metal laser sintering
Proceedings of EUROMAT 2015, Warsaw (PL)
Autore/i: Barucca, Gianni; Bassoli, E.; Denti, L.; Fiori, Fabrizio; Gatto, A.; Girardin, Emmanuelle; Mengucci, Paolo
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251538

Biomedical alloys produced by direct metal laser sintering
Multinational Conference on Microscopy 2015 (MCM 2015)
Autore/i: Mengucci, Paolo; Barucca, Gianni; Gatto, A.; Bassoli, E.; Iuliano, L.; Rutkowski, B.
Luogo di pubblicazione: Eger
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Direct Metal Laser Sintering (DMLS) is an advanced manufacturing technology based on layer-by-layer deposition for the production of complex functional mechanical parts. In the DMLS technology, a solid-state laser controlled by a scanning system sinters successive layers of a metal powder in accordance to the previously realized CAD/CAM model. In the biomedical field, DMLS is a promising technology for prosthetic applications where complex geometries, low volumes and strong individualization are required. Co- and Ti-based alloys are extensively used in biomedical applications due to their mechanical properties and biocompatibiliy. In this study, a Co-Cr-Mo composition suitable for biomedical applications and a Ti-6Al-4V alloy were produced by the DMLS technology. In order to study the structure stability of the alloys, samples were submitted to thermal treatments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235064

Synthesis and characterization of PLD CoFe thin films as a function of composition and deposition conditions
Proceedings of Magnet 2015, Bologna (IT)
Autore/i: Peddis, D.; Barucca, Gianni; Varvaro, G.; Testa, A. M.; Mengucci, Paolo; Agostinelli, E.; Laureti, S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251533

Flux Pinning in Y- and Ag-Doped MgB2
ADVANCES IN MATERIALS PHYSICS AND CHEMISTRY
Autore/i: Dyson, Jack; Rinaldi, Daniele; Barucca, Gianni; Albertini, Gianni; Sprio, Simone; Tampieri, Anna
Classificazione: 1 Contributo su Rivista
Abstract: High temperature superconductor research is presently concentrated upon the flux pinning properties of the Abrikosov lattice of the mixed-mode superconducting phase. The temperature thermal fluctuations, current and magnetic field unpin the flux vortices and so cause electromagnetic resistivity in high temperature superconductors. Materials with higher vortex pinning exhibit less resistivity and are more attractive for industrial uses. In the present article, we measured and correlated the pinning flux energy barrier, determined by AC magnetic measurements, and transmission electron microscopy measurements to the critical current Jc in Yttrium- and Silver-doped MgB2 superconductors. The energy of the flux vortex was evaluated as a function of the magnetic field. The energy barrier curves suggest an optimal doping level to occur in doped materials. This result only depends on the optimal size and distribution of precipitates, and not on their chemical composition. The energy barriers have been compared with that of undoped MgB2 in literature.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/228103