Half-metallic magnetism of Co2CrX (X=As, Sb) Heusler compounds: An ab initio study

In this study, we present the electronic, magnetic, and structural properties of two novel half-metallic full-Heusler compounds, Co2CrAs and Co2CrSb, in cubic L21 geometry. The calculations are based on the density functional theory within plane-wave pseudopotential method and spin-polarized generalized gradient approximation of the exchange-correlation functional. The electronic band structures and density of states of the systems indicate half-metallic behavior with vanishing electronic density of states of minority spins at Fermi level, which yields perfect spin polarization. The calculated magnetic moments of both systems in L21 structure are 5.00 μBμB, which are largely localized on the chromium site. The energy gaps in minority spin states are restricted by the 3d-states of cobalt atoms on two different sublattices. The formation enthalpies for both structures are negative indicating stability of these systems against decomposition into stable solid compounds.

Research highlights
► Co2CrAs and Co2CrSb compounds show half-metallic behavior in L21 structure.
► Energy gaps in minority spin channel are due to the d-states of cobalt atoms.
► Both systems have 5.00 μBμB magnetic moments, which are largely localized at Cr site.
► Formation enthalpies are negative indicating thermochemical stability.