MAGNETOCALORIC PROPERTIES OF Fe-Rh-(Z) (Z = Pd, Ni) ALLOYS FROM AB INITIO AND MONTE CARLO CALCULATIONS

摘要

In this work, we theoretically investigated the magnetic and magnetocaloric properties of Fe-Rh-(Z) (Z = Pd, Ni) alloys by using the ab initio and Monte Carlo approaches. The equilibrium structural and magnetic reference states as well as the magnetic exchange coupling constants for both low- and high-temperature phases were determined by means of first-principles calculations. In order to obtain the temperature dependencies of magnetic and magnetocaloric properties, we used the Potts-Blume-Emery-Griffiths lattice-spin model with parameters obtained from ab initio calculations as input data. As the result, the temperature behaviors of magnetization, specific heat, magnetic entropy as well as magnetocaloric effect (ΔS and ΔT_(ad)) were obtained at the magnetic field change of 2 T by using the classical Monte Carlo routine. The obtained results are found in a good agreement with available experimental data.