An ab initio study of Co–Cr(V) disorder effects on the electronic structure and magnetic properties of Co2Cr1−xVxAl

We have investigated the electronic and magnetic properties of V-doped Co2Cr1−xV xAl (x=0.0x=0.0, 0.25, 0.5, 0.75, 1.0) using first-principles density functional theory within the generalized gradient approximation (GGA) scheme. Our results reveal that the Co(Cr) site magnetic moment increases with V doping and that the total spin moment of these compounds in the half-metallic ferromagnetic ground states decreases linearly. We also have performed electronic structure calculations for Co2Cr1−xV xAl with positional disorder at the Co/Cr(V) sites. Disordering is found to destroy the half-metallic nature of the ordered compound; moreover, the disorder leads to a significant reduction in the net magnetic moment. The experimentally observed reduction of the magnetic moment mainly arises from an antiferromagnetic coupling of the antisite Cr(V) with the first-nearest-neighboring ordinary-site Cr in a disordered sample.