2p Elements Induced Half-Metallic Ferromagnetism in Alkaline Earth Chalcogenides

First principles calculations have been carried out to study the possibility of half-metallic ferromagnetism in alkaline earth chalcogenides in the presence of 2p (B, C and N) elements. Half-metallic ferromagnetism is found in alkaline earth chalcogenides by the substitution of C and N in anion site with total magnetic moment of 2.00 mu(B) and 1.00 mu(B) per formula unit respectively. Calculations show that B doping in alkaline chalcogenides does not lead to half-metallic ferromagnetism. Analysis of the density of states and magnetic moment indicates that the half-metallic ferromagnetism is mainly due to the spin-polarization of p-like states of dopants around the Fermi Level and the hybridization between the p-like states of dopants and d-like states of alkaline earth elements. Total energy calculations show that ferromagnetic state is more stable than nonmagnetic state.