Electronic and Magnetic Properties of CaS sub(0.875)M sub(0.125) (M = C, Si, Ge and Sn) by First Principles Theory

The total energy, energy bands, density of sates and half-metallic ferromagnetism of CaS sub(0.875)M sub(0.125) (M = C, Si, Ge and Sn) have been studied using band structure calculation methods namely full potential linearized augmented plane wave (EP-LAPW) as well as tight binding linear muffin orbital (TB-LMTO) method. We find that within the generalized gradient approximation (GGA) all dopants induce half-metallic ferromagnetism in CaS, whereas in the case of local spin density approximation (LSDA) C- doping only induce half-metallicity in CaS. The calculated magnetic moment is found to be 2.00 mu sub(B) per formula unit. The magnetism arises mainly from the p states of dopant atoms. The ground state properties such as lattice constant, total energy difference between non-magnetic and ferromagnetic state, total and partial magnetic moments have been calculated. Within the GGA calculation all dopants enhance the stability of ferromagnetic state.