Structural, electronic and magnetic properties of Cd1–xTMxS (TM=Co and V) by ab-initio calculations

Abstract

The structural, electronic and ferromagnetic properties of Cd1−xTMxS (TM=Co and V) compounds at x=0.25, 0.50 and 0.75 in zinc blende (B3) phase, have been investigated using all-electron full-potential linear muffin tin orbital (FP-LMTO) calculations within the frame work of the density functional theory and the generalized gradient approximation. The electronic properties exhibit half-metallic behavior at x=0.25, 0.50, and 0.75 for Cd1–xVxS and x=0.25 and 0.50 for Cd1−xCoxS, while Cd1−xCoxS with x=0.75 is nearly half-metallic. The calculated magnetic moment per substituted transition metal (TM) atom for half-metallic compounds is found to be 3µB, whereas that of a nearly half-metallic compound is 2.29µB. The analysis of band structure and density of states shows that the TM-3d states play a key role in generating spin-polarization and magnetic moment in these compounds. Furthermore, we establish that the p–d hybridization reduces the local magnetic moment of Co and enhances that of V from their free space charge value of 3µB and creates small local magnetic moments on nonmagnetic Cd and S sites. The exchange constant N0α and N0β have been calculated to validate the effects resulting from exchange splitting process.