Half-metallic ferromagnetism in ZnCrTe and CdCrTe: Ab initio study

Using the first-principles method, we investigate the structural, electronic and magnetic properties of the diluted magnetic semiconductors ZnCrTe and CdCrTe in the zinc blende phase with 25% of Cr. We have treated the ferromagnetic and antiferromagnetic phases. The calculations are performed by a developed full-potential augmented plane wave plus local orbitals (FP-L/APW + lo) method within the spin density functional theory. As exchange–correlation potential we used the new generalized gradient approximation GGA form and GGA + U. Structural properties are determined from the total energy calculations and we found that these compounds are stable in the ferromagnetic phase. We discuss the electronic structures, total and partial densities of states and local moments. Furthermore, we predict the values of spin-exchange splitting energies Δx(d) and Δx(pd) and exchange constants N0α and N0β produced by the Cr 3d states. Finally, we demonstrate that the half-metallicity is robust with respect to lattice contraction.