Magnetic structure and magnetocaloric properties of Ho(Co1-xFex)(2) quasibinary intermetallic compounds

AbstractA study of crystal and magnetic structures, heat capacity, magnetic and magnetocaloric properties of Ho(Co1-х Feх)2 (with increasing x from 0 to 0. 2) intermetallic compounds has been undertaken. Phase composition was controlled by X-ray diffraction analysis. Neutron diffraction experiment was performed at temperatures of 78 and 293K. Magnetic properties were measured within the temperature range 5÷325K in magnetic fields up to 70 kOe. It was shown that considerable maximum broadenings on the temperature dependence of magnetic entropy change is observed with iron concentration increase. The avarage magnetic moment of Ho ions in their sublattice decreases from 10μB for HoCo2 to 9μB for Ho(Co0.8Fe0.2)2 that can be connected with the existence of the umbrella-like (canting) magnetic structure in Ho-sublattice

Study of semi-polar gallium nitride grown on m-sapphire by chloride vapor-phase epitaxy

In this study, we analyzed the result of the influence of the non-polar plane of a sapphire substrate on the structural, morphological, and optical properties and Raman scattering of the grown epitaxial GaN film. It was found that selected technological conditions for the performed chloride-hydride epitaxy let us obtain the samples of structurally qualitative semi-polar wurtzite gallium nitride with (11¯22) orientation on m-sapphire. Using a set of structural and spectral methods of analysis the structural, morphological, and optical properties of the films were studied and the value of residual bi-axial stresses was determined. A complex of the obtained results means a high structural and optical quality of the epitaxial gallium nitride film. Optimization of the applied technological technique in the future can be a promising approach for the growth of the qualitative GaN structures on m-sapphire substrates