Ab initio study of V doping effects on electronic structure and magnetic properties in Co2Fe1−xV xAl

We have investigated the electronic and magnetic properties of the doped Heusler alloys Co2Fe1−xV xAl (x=0x=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−xV xAl 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−xV xAl alloys. Furthermore, we found that the spin polarization increases with V doping in Co2Fe1−xV xAl with ordered L21L21 and disordered B2 structures. Detailed calculations show that the stability of the L21L21 structure will be enhanced with increasing V content. The results are compatible with experiments.

► The μFe increases while the μCo decreases with V doping. ► The Al–Fe(V-type disorder is more stable than the Co–Fe(V)-type disorder. ► The spin polarization increases with V doping in Co2Fe1−xV xAl. ► The stability of the L21L21 structure will be enhanced with V doping in Co2Fe1−xV xAl.