First-principle investigation of magnetic coupling mechanism in hypothesized a-site-ordered perovskite YMn₃Sc₄O₁₂

We have systematically investigated the electronic and magnetic properties of hypothesized A-site-ordered perovskite YMn₃Sc₄O₁₂ using first-principle calculation based on the density functional theory. Our calculated results predict that YMn₃Sc₄O₁₂ is both thermodynamically and mechanically stable and its ground state is antiferromagnetic insulator. The Mn(3+) is in the high-spin state. More importantly, by comparison to YMn₃Sc₄O₁₂, we point out that the empty Sc 3d orbital provides the Mn--O--Sc--O--Mn superexchange interaction, which is similar to its isostructural perovskite CaCu₃Ti₄O₁₂, and enhances the antiferromagnetic interaction between Mn ions. From these calculations, we can clearly see that the empty 3d orbital plays an important role to realize superexchange interaction.