Spin-polarized structural, electronic and magnetic properties of diluted magnetic semiconductors Cd1−xMnxTe in zinc blende phase

We have investigated the structural, electronic and magnetic properties of the diluted magnetic semiconductor (DMS) Cd1−xMnxTe (for x=0.75 and 1.0) in the zinc blende (B3) phase by employing the ab-initio method. Calculations were performed by using the full potential linearized augmented plane wave plus local orbitals (FP-L/APW+lo) method within the frame work of spin-polarized density functional theory (SP-DFT). The electronic exchange-correlation energy is described by generalized gradient approximation (GGA). We have calculated the lattice parameters, bulk modulii and the first pressure derivatives of the bulk modulii, spin-polarized band structures, and total and local densities of states. We estimated the spin-exchange splitting energies Δx(d) and Δx(pd) produced by the Mn3d states, and we found that the effective potential for the minority spin is more attractive than that of the majority spin. We determine the s–d exchange constant N0α (conduction band) and p–d exchange constant N0β (valence band) and these somewhat agree with a typical magneto-optical experiment. The value of calculated magnetic moment per Mn impurity atom is found to be 4.08 μB for Cd0.25Mn0.75Te and 4.09 μB for Cd0.0Mn1.0Te. Moreover, we found that p–d hybridization reduces the local magnetic moment of Mn from its free space charge value of 5.0 μB and produces small local magnetic moments on the nonmagnetic Cd and Te sites.

Research highlights
► The p-d hybridization reduces the local magnetic moment of Mn in Cd1-xMnxTe.
► The p-d hybridization produces small local magnetic moments on the atom Cd and Te sites.
► The Mn impurity adds no hole carriers to the perfect CdTe crystal.