Prediction of half-metallic ferromagnetism (HMF) in hypothetical Heusler compound Co2VSb using modified Becke Johnson (mBJ) potential

In search of half-metallic ferromagnetism, we have studied the electronic and magnetic properties of Co2VSb by using the different tools like GGA, LSDA+U and mBJ potential based on density functional theory (DFT). The compound Co2VSb is analogous to Co2VAl, Co2VSn and Co2VGa , these compounds were studied theoretically and experimentally by Buschow and Engen. We expect the similar kind of properties from Co2VSb as that of Co2VAl, Co2VSn and Co2VGa. 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 Å. 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.