First principle investigation of structural, electronic and magnetic properties of cubic Cd0.9375TM0.0625S (TM=Ni, Co and Fe)

In this study, we investigated the structural, electronic and magnetic properties of Cd0.9375TM0.0625S (TM=Ni, Co and Fe) compounds in zinc blende (B3) ferromagnetic phase 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 analysis of electronic structures shows that Cd0.9375Ni0.0625S, Cd0.9375Co0.0625S and Cd0.9375Fe0.0625S compounds are half-metallic ferromagnets with 100% spin polarization at the Fermi level. This half-metallic behavior is confirmed by the total calculated magnetic moment per Ni, Co and Fe substituted transition metal (TM) atom, which is found to be 2 µB, 3 µB and 4 µB for Cd0.9375TM0.0625S (TM=Ni, Co and Fe) compounds, respectively. Furthermore, we found that the TM-3d states are responsible for generating spin-polarization and magnetic moment in these compounds and we establish that the p-d hybridization reduces the local magnetic moment of TM atoms from its free space charge value and produces small local magnetic moments on nonmagnetic Cd and S host sites. Also, we predicted exchange splitting energy Δx(pd) and exchange constants N0α and N0β. The calculated values validate the ferromagnetic nature of these compounds.