First Principles Calculations for Valence States of Mn in SrTiO3

摘要

The valence change mechanism of doped Mn in SrTiO3 has been discussed on the basis of the first-principles calculation results. These results show that the crystal with Mn²⁺ is stabilized by a peculiar tilting deformation of the MnO6 octahedron, whereas the crystal with Mn⁴⁺ does not exhibit such tilting. The valence of Mn is closely related to the lattice deformation, and the experimentally observed change in the valence of Mn in SrTiO3 can be well explained by the thermal excitations of the tilting modes of MnO6.