Ab initio study of V doping effects on electronic structure and magnetic properties in Co2Fe1-xVxAl

We have investigated the electronic and magnetic properties of the doped Heusler alloys Co2Fe1-xVxAl (x = 0, 0.25, 0.5, 0.75, 1) using first-principles density functional theory within the generalized gradient approximation (GGA) scheme. The calculated results reveal that with increasing V content the lattice parameter slightly increases. The magnetic moment of the Fe sites increases while the magnetic moment of the Co sites decreases with V doping; the total spin moment of these compounds linearly decreases. We also have performed the electronic structure calculations for Co2Fe1-xVxAl with positional disorder of Co-Fe(V) type and Al-Fe(V) type. It is found that formation of Al-Fe(V)-type disorder is more favorable than that of Co-Fe(V)-type disorder in Co2Fe1-xVxAl alloys. Furthermore, we found that the spin polarization increases with V doping in Co2Fe1-xVxAl with ordered L2(1) and disordered B-2 structures. Detailed calculations show that the stability of the L2(1) structure will be enhanced with increasing V content. The results are compatible with experiments. (C) 2012 Elsevier Ltd. All rights reserved.