Prediction of half-metallic ferromagnetism (HMF) in hypothetical Heusler compound Co sub(2)VSb using modified Becke Johnson (mBJ) potential

In search of half-metallic ferromagnetism, we have studied the electronic and magnetic properties of Co sub(2)VSb by using the different tools like GGA, LSDA+U and mBJ potential based on density functional theory (DFT). The compound Co sub(2)VSb is analogous to Co sub(2)VAl, Co sub(2)VSn and Co sub(2)VGa , these compounds were studied theoretically and experimentally by Buschow and Engen. We expect the similar kind of properties from Co sub(2)VSb as that of Co sub(2)VAl, Co sub(2)VSn and Co sub(2)VGa. The mBJ potential is considered to be more effective as compared to LDA and GGA which gives higher value of band gap. The theoretical lattice constant obtained from volume optimization is 6.072 Aa. The calculated value of energy gaps was found to be 0.20 eV, 1.00 eV and 1.30 eV for GGA, LSDA+U and mBJ respectively. Our results of band gap calculation predicts that mBJ overestimate the results of GGA, LSDA and LSDA+U.