Spin, Charge, and Orbital Ordering in 3d Transition-Metal Oxides Studied by Model Hartree-Fock Calculation

Abstract

We have spin, charge, and orbital ordered states in the perovskite-typelattice models for La2-xSrxCuO4, La2-xSrxNiO4, and Pr1-xCaxMnO3 by meansof unrestricted Hartree-Fock calculations. Present calculations showthat, although the vertical charge stripes along the (1,0) direction ofthe Cu-O square lattice are favored in the cuprates with thecharge-transfer energy Delta of similar to2 eV, the diagonal stripesalong the (1,1) direction are stable in the nickelates with Delta ofsimilar to4 eV. For the manganites with Delta of similar to4 eV, it hasbeen found that the (1,1,0)-type charge-ordered state with the orbitalordering at the Mn3+ sites are stabilized by the Jahn-Teller distortionat the Mn3+ sites.