First principle calculations for pressure induced structural phase transitions of Fe doped in SrMnO3

The pressure induced structural phase transition of Fe doped in SrMnO3 have been investigated using the pseudo-potential plane wave method within the generalized-gradient approximation plus on site repulsion U (GGA + U) method by first principles. The cooperative Jahn–Teller distortion is not found at zero pressure. By performing a structural phase stability analysis, the phase transition occurs between the cubic and tetragonal phase at 25.0 GPa. As pressure above 25.0 GPa, the different Mn–O and Fe–O bond lengths indicate that there is a strong Jahn–Teller distortion of the MnO6 and FeO6 octahedron, which is associate with structural transition. The Jahn–Teller distortion stabilizes a chain like antiferromagnetic (C-AFM) ground state. The band gap and density of states show that the electrical resistivity decreased as a result of the phase transition. The result gives an antiferromagnetic ground state for SrMn0.875Fe0.125O3 agreeing very well with the experimental report.