Spin, charge, and orbital ordering in Mn perovskite oxides studied by model Hartree-Fock calculations

The spin, charge, and orbital ordering in (Formula presented)MnO(Formula presented) and (Formula presented)MnO(Formula presented)=rare earth, (Formula presented)=Sr, Ca) has been studied by means of unrestricted Hartree-Fock calculations on the multiband (Formula presented) model. Since the superexchange interaction between the Mn(Formula presented) and Mn(Formula presented) sites depends on which type of (Formula presented) orbital is occupied at the Mn(Formula presented) site, antiferromagnetic states such as (Formula presented) type and (Formula presented) type favor a specific orbital ordering. It is shown that the Jahn-Teller distortion consistent with the orbital ordering plays an essential role in stabilizing the experimentally observed antiferromagnetic states.