RECENT ADVANCES IN THE THEORY OF MAGNETISM OF NIAS-TYPE TRANSITION-METAL CHALCOGENIDES AND PNICTIDES

Magnetism of NiAs-type transition-metal compounds is studied from the viewpoint of the itinerant electron. Electronic nonmagnetic bands of MAs and MSb (M equals Cr, Mn, Fe, Co, Ni) and ferromagnetic bands of MnAs and MnSb are calculated by the self-consistent APW method. The obtained ferromagnetic moments are in good agreement with observations. The anomalous temperature dependence of the paramagnetic susceptibility observed in MnAs, MnAs//1// minus //xP//x, FeAs and CoAs is well explained on the basis of spin fluctuation theory, by taking account of characteristic behavior of the density of states obtained for each compound.