Study of the Magnetic Properties of CdMnTe_1−y N _y and CdMnTe with Defects by Ab Initio Calculations

Abstract

We performed ab initio calculations to investigate the effect of the doping in CdMnTe_1−y N _y and also of the defects in CdMnTe alloy. Moreover, we studied the magnetic properties in the both cases. Our calculations were carried out using the Akai-Korringa-Kohn-Rostoker method combined with coherent potential approximation (KKR-CPA) within the spin-polarized density functional theory (DFT) and local density approximation (LDA). The density of state (DOS) has also been calculated for different dopants and defect concentrations. The compound Cd_1−xMn _{x = 0.38}Te is the diluted magnetic semiconductor (DMS) we studied in one of our earlier works (Ait Raiss, A. et al., doi:10.1016/j.jmmm.2015.02.077). The p-band of the doping with nitrogen (N) atoms lies in the Fermi level, which is similar to the half-metallic behavior. The stabilized magnetic state in all these concentrations is the disordered local moment (DLM) state. The defect effect depends on their positions, either these defects are in the Cd sites or in telluride (Te) sites. In the both cases, we obtained different stable magnetic states. These states are either ferromagnetic or DLM ones. We also examined the effect of the N doping atoms on the Faraday rotation as a magneto-optical property of CdMnTe.