Roles of Excess Atoms in Electronic and Magnetic Properties of Fe_2+xV_1−xZ (Z = Al, Ga)

抄録

To expand our knowledge of Fe_2+xV_1−xZ (Z = Al, Ga), band calculations (LMTO-ASA) have been performed for several x values (x=0,±0.125,±0.25) with a supercell method. Obtained density of states and magnetic moments indicate that excess atoms, which are introduced instead of the original Fe or V atom in Fe₂VZ, bring a drastic change in electronic and magnetic properties of Fe₂VZ. The existence of those atoms causes the collapse of the gap (or pseudogap) and the change from nonmagnetic to magnetic states. In the magnetic state, those atoms carry 2.5–2.6μ_B for x>0 and 0.7–1.1μ_B for x<0.