First‐principle investigation of magnetic coupling mechanism in hypothesized A‐site‐ordered perovskite YMn 3 Sc 4 O 12

We have systematically investigated the electronic and magnetic properties of hypothesized A‐site‐ordered perovskite YMn 3 Sc 4 O 12 using first‐principle calculation based on the density functional theory. Our calculated results predict that YMn 3 Sc 4 O 12 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 YMn 3 Al 4 O 12 , we point out that the empty Sc 3 d orbital provides the MnOScOMn superexchange interaction, which is similar to its isostructural perovskite CaCu 3 Ti 4 O 12 , and enhances the antiferromagnetic interaction between Mn ions. From these calculations, we can clearly see that the empty 3 d orbital plays an important role to realize superexchange interaction. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011