Correlation effects on the electronic structure of Co2VGa1-xSix (x=0, 0.25, 0.5, 0.75 and 1) quaternary Heusler alloys: First-principles calculations

In this study, density functional full-potential linearized augmented-plane wave (FP-LAPW) calculations have been conducted to investigate the structural, electronic and magnetic properties of the quaternary full Heus ler compounds Co2VGa1-xSix (x = 0, 0.25, 0.5, 0.75 and 1). We adopted the generalized gradient approximation (GGA) method to estimate the exchange correlation potential and the GGA + U (i.e. Hubbard correction) calculations in accurately characterizing the correlation effects. The lattice parameter a(0), bulk modulus B-0 and magnetic moment M at the equilibrium state were found to be in good agreement with the experimental data. The calculated density of states of the systems confirm the metallic property for the concentrations x = 0; 0.25 and 0.5, whereas the compositions x = 0.75 and 1.0 exhibit half-metallic nature. The GGA + U gave higher value than that obtained by GGA for the calculate magnetic moments. This work highlights clearly the role of the correlated electrons processing for an accurate description of these compounds. (C) 2018 Elsevier B.V. All rights reserved.