Alkaline-earth oxides (AeO; Ae = Mg, Ca and Sr) doped with group VII (F, Cl, Br and I) elements as promising spin-injector materials have been investigated by using first principles full-potential linearized augmented plane-wave method. The substitution of group VII elements turns the insulator host AeO into ferromagnetic and some of them exhibit half-metallic ferromagnetic property with an integer magnetic moment of 3.00 μB/cell. The spin-resolved electronic band structure and density of states show that the Ae0.875M0.125O compounds exhibit spin-dependent transport properties, in which the conduction proceeds entirely via the minority spin state in F-doped AeO and through majority spin state in Cl, Br and I-doped CaO and SrO. The comparison of local spin density approximation and generalized gradient approximation is also carried out. The results show that the origin of ferromagnetism in Ae0.875M0.125O is attributed to the p-p hybridization interaction betwwn group VII elements and oxygen.
Alkaline-Earth Oxides, First Principles Calculation, Half-Metallic Ferromagnet, Non-Magnetic Impurity.