Electronic structure and magnetism of MnFeP1−xSix alloys from first-principles calculations

First-principles calculations of electronic structure and magnetic properties based on density-functional theory were performed for MnFeP_1−xSi_x (0.44?x?0.60) alloys which are considered as promising magnetocaloric refrigerants. We used the full-potential APW+lo method and treated the random order of P(Si) atoms in the ZrNiAl-type structure in a virtual-crystal approximation. A non-monotonic behavior of the alloy magnetization as a function of x was obtained, in qualitative agreement with experiment, and explained in terms of the spin-polarized densities of states.