Modified Becke-Johnson approach for governing half metallic ferromagnetism in Cr-doped GaP DMS compound

The electronic and magnetic properties of Ga1-xCrxP Dilute Magnetic Semiconductor (DMS) compound at doping concentration, x = 0.125 has been calculated using full potential linearized augmented plane wave (FPLAPW) method. The exchange and correlation (XC) effects are taken into account by a semi local, orbital independent modified Becke-Johnson (mBJ) potential as coupled with Local Density Approximation (LDA). Our calculation shows that Cr induces the ferromagnetism in this compound and there is large half metallic (HM) gap appearing in the minority spin channel. We observed that mBJLDA potential enhances the HM gap by similar to 0.25 eV as compared to from its value in Generalized Gradient Approximation (GGA). The improved HM gap can be understood in terms of the mBJLDA-enhanced spin exchange splitting.