[GS_C_MS] First-principles study of hard magnetic materials
ABSTRACT
Modern high-performance permanent magnets are rare-earth magnets which contain 3d transition metals and rare-earth elements as their main components. A rare-earth magnet compound can be regarded as a coupled system of 3d and 4f electrons which results in high magnetization, high Curie temperature and high magnetocrystalline anisotropy. In this talk, I will start with first-principles calculation techniques for finite-temperature magnetization. Effects of electron-phonon and electron-magnon interactions are approximately treated in the coherent potential approximation, and the Slater-Pauling curve at finite temperature is presented. I will also discuss exploration of iron-based rare-earth compounds for designing novel magnets. Stability of the TbCu7-type structure, in which pairs of iron atoms are randomly distributed, is evaluated in the cluster expansion method, from which the composition range of iron rich phase is determined.
