THEORETICAL-STUDY OF MAGNETIC-ORDERING OF CU2SB-TYPE INTERMETALLIC COMPOUNDS

Electronic band structures of the Cu2Sb-type intermetallic compounds a re calculated by using a self-consistent augmented plane wave (APW) or a linearized APW (LAPW) method. In order to clarify the driving force s for different kinds of magnetic orderings in the CU2Sb-type compound s, the instability of the non-magnetic phase against formation of the magnetic orderings are studied on the basis of the Hubbard Hamiltonian . The magnetic phase diagram is constructed as a function of the intra -atomic Coulomb interaction and the electron number. The bonding natur e of the electronic band near the Fermi level as well as a nesting eff ect of the Fermi surface plays the important role in causing the diffe rent kinds of magnetic orderings observed in the CU2Sb-type compounds.