First principles study of half-metallic ferromagnetism in Cr-doped CdTe

We report a systematic study of the structural, electronic and magnetic properties of Cr-doped CdTe for various Cr concentrations x (=0.25, 0.5, 0.75 and 1.0) using first principles calculations based on the density functional theory (DFT). The electronic band structure of the alloy has been calculated using the Wu–Cohen (WC) as well as the Angel-Vosko (EV) generalized gradient approximation (GGA) for the exchange-correlation potential. The analysis of the density of states (DOS) curves shows the half-metallic ferromagnetic character with half-metallic gap more than 0.52 eV. While the origin of half-metallic ferromagnetism is explained, the band structure calculations are used to determine s (p)–d exchange constants N0α (conduction band) and N0β (valence band) that agree with typical magneto-optical experiment. It is found that the p–d hybridization reduces the magnetic moment of Cr from its free space charge value and produces small magnetic moments on the Cd and Te sites. Lastly, we discuss the robustness of half-metallicity with respect to the variation of lattice constants of the CrxCd1−xTe alloys.

► Spin effect theoretical studies on Cr-doped CdTe have been performed.
► First principles FP-LAPW+lo approach based on DFT is used for this purpose.
► Structural and electronic band parameters have been calculated and discussed.
► Values of exchange constants, magnetic moments and robustness are estimated.