First principles calculation of elastic and magnetic properties of Cr-based full-Heusler alloys

We present an ab-initio study of the elastic and magnetic properties of Cr-based full-Heusler alloys within the first-principles density functional theory. The lattice constant, magnetic moment, bulk modulus and density of states are calculated using the full-potential nonorthogonal local-orbital minimum basis (FPLO) code in the Generalized Gradient Approximation (GGA) scheme. Only the two alloys Co sub(2)CrSi and Fe sub(2)CrSi are half-metallic with energy gaps of 0.88 and 0.55 eV in the spin-down channel respectively. We have predicted the metallicity state for Fe sub(2)CrSb, Ni sub(2)CrIn, Cu sub(2)CrIn, and Cu sub(2)CrSi alloys. Fe sub(2)CrSb shows a strong pressure dependent, e.g. exhibits metallicity at zero pressure and turns into a half-metal at P > or = 10 GPa. The total and partial magnetic moments of these alloys were studied under higher pressure, e.g. in Co sub(2)CrIn, the total magnetic moment is almost unchanged under higher pressure up to 500 GPa.