Atomic disorder effects on half-metallicity of the full-Heusler alloys Co2(Cr1-xFex)Al:: A first-principles study -: art. no. 144413

We investigate the atomic disorder effects on the half-metallicity of the full-Heusler alloy Co-2(Cr1-xFex)Al from first principles by using the Korringa-Kohn-Rostoker method with the coherent potential approximation. Our results show that disorder between Cr and Al does not significantly reduce the spin polarization of the parent alloy Co2CrAl, while disorder between Co and Cr makes a considerable reduction of the spin polarization. It is observed that the spin polarization of Co-2(Cr1-xFex)Al decreases with increasing Fe concentration x in both the ordered L2(1) and the disordered B2 structures, and that the effects of the disorder on the spin polarization is significant at low Fe concentrations. The results suggest that a highly spin-polarized ferromagnet with high Curie temperature will be obtained if a Co-2(Cr1-xFex)Al with the ordered L2(1) structure can be fabricated at low Fe concentrations.