3^rd International Conference on Magnetism and Magnetic Materials October 22-23, 2018 Rome, Italy

Igor V Shchetinin has completed his PhD in the year 2012 from National University of Science and Technology. He is the head of X-ray structure analysis and diagnostic of materials laboratory. He has published more than 60 papers in reputed journals and has been serving as an Editorial Board Member of repute.

Compounds based on Fe and rare earth elements with the structural type ThMn12 have been known for more than 30 years and have fundamental magnetic properties comparable to the compound Nd2Fe14B. Nitrides of NdFe12 compound have higher properties than those of Nd2Fe14B compound: saturation magnetization 1.66 T, Curie temperature 550°C and anisotropy field 6.4 MA/m. However binary compounds RFe12 (R is rare-earth element) are stable only in the thin films forms. To stabilize this phases with ThMn12 structural type transition metals that replace Fe are used RFe12-xMx (where M = Al, Cr, V, Ti, Mo, W, Si or Nb) At present time these alloys have no practical application due to small values of hysteresis properties compared to the Nd-Fe-B system. In this regard, investigation of structure formation and magnetic properties of NdFe11Ti alloys quenched from the liquid state and subjected to heat treatment is an urgent task. As a result of these studies, methods and regimes for producing of NdFe11Ti-NdFe11TiN compounds have been tested: melting, homogenizing annealing, quenching from a liquid state, and nitriding. It is shown that homogenizing annealing at a temperature of 1100°C for 168 h makes it possible to obtain a ferromagnetic phase with a structural type of ThMn12. An almost single-phase state (97%) was produced by quenching from the liquid state without using prolonged annealing which increases the grain size of the NdFe11Ti phase to about 150 nm. It is shown that nitriding of the alloy leads to an increase in main magnetic hysteresis properties. The maximum magnetic hysteresis properties were obtained using a combination of quenching methods from the liquid state and nitriding: Hc = 1053 Oe, σr = 46 emu/g, σs = 139 emu/g.

Igor V Shchetinin completed his PhD in the year 2012 from National University of Science and Technology. He is the head of X-ray structure analysis and diagnostic of materials laboratory. He has published more than 60 papers in reputed journals and has been serving as an Editorial Board Member of repute.

The nitrides of the Sm2Fe17-based alloys are promising for the development of permanent magnets because they have a high magnetic crystalline anisotropy constant, Curie temperature, and are cheaper than compounds like Nd2Fe14B. In this connection, study of structure formation and magnetic properties of alloys based on nitrides of the Sm2Fe17 compound obtained by the methods of extreme effects is the actual task. It this work, we show that alloys in the initial state and after the hydrogenation and dehydrogenation processes contained the main phase of Sm2Fe17 and a small amount (<2%) of α-Fe nitriding resulted in increased of Sm2Fe17 lattice spacing without formation of new phases. After severe plastic deformation by torsion (SPDT), diffraction patterns of the alloys revealed a strong broadening of the diffraction lines which indicated the formation of a dispersed structure and was confirmed by SEM data: the formation of an equiaxial structure in the sample with an average grain size of 20 nm. In addition, according to X-ray diffraction analysis, the fraction of α-Fe increased in the SPDT process due to the local heating of the sample and leads to decomposition of Sm2Fe17N2.8 phase. The hysteretic properties of the alloys changed in an extreme: under deformations with n = 2.5, the coercive force was increased to 6.5 kOe, and an increase in the degree of deformation led to a decrease in the coercive force, with the formation of a characteristic loop of magnetic hysteresis. As a result of the deformation at 77 K, nitride decomposition was not observed which confirms the heating of the material during deformation at room temperature.

Ahmed Faramawy is the PhD student of NanoStructures Group from the Dept. of Physics and Astronomy in the University of Padova (via Marzolo 8, I-35131 Padova, Italy).

Fe doped ZnO (FeZO) thin films were deposited using magnetron co-sputtering (DC for Fe and RF for ZnO) on silica and silicon substrates. To better control the Fe-doping in the 1% atomic range, instead of reducing the DC power (which produced instabilities of the DC source), we performed the DC sputtering through a grid with different mesh size to block part of the Fe atoms. The structural, optical and magnetic properties of 150 nm thick FeZO films were investigated. Single phase hexagonal wurtzite structures in all samples were confirmed by GIXRD. RBS and EDX were used to determine the elemental composition and stoichiometry of the ZnO films doped with Fe. A variation of the FeZO bandgap from 3.21 eV (pure ZnO) to 3.33 eV (5% Fe in ZnO) has been obtained from the optical transmittance using UV-Vis optical spectroscopy. Moreover, the room temperature M–H hysteresis loops for FeZO films were investigated by vibrating sample magnetometer (VSM). A ferromagnetic behavior was obtained in the pure ZnO film, possibly due to surface defects such as oxygen vacancies, whereas a paramagnetic one was found for the FeZO ones. These various properties make FeZO in thin film form a promising candidate material in wide range applications in photocatalysis and in magneto-optical devices, which we plan to investigate in our future work.