Study of the half-metallic materials double perovskites Sr ₂ZnBO₆ (B=Tc, Re, Ru, Os, Co, Pd, and Au) via first-principle calculations

Based on the density functional theory calculations, the structural optimization, magnetic stable phase, and electronic structure of the double perovskites Sr₂ZnBO₆ (B=Tc, Re, Ru, Os, Co, Pd, and Au) were investigated with full structural optimization by using the generalized gradient approximation (GGA) and by adding the correlation effect (GGA+U). The results indicate that all compounds can be stable half- metallic ferromagnetic materials in the GGA(+U) scheme with a spin splitting e_g band of the B ion, which causes half-metallicity at the Fermi level except Sr ₂ZnCoO₆ becomes a conductor in GGA+U scheme. We suggest that the double exchange interaction dominates the half metallicity and magnetism in these materials.