抄録 Possible ordered phases in perovskite manganites are investigated in the framework of
an effective spin Hamiltonian for the atomic limit. Using the mean-field approximation …

We present an exact diagonalization study for perovskite manganites using an effective
Hamiltonian which includes a coupling between the spin and orbital degrees of freedom …

The spin and orbital phase diagram for perovskite manganites is investigated as a function
of temperature and hole concentration. The superexchange and double exchange …

Roles of orbital degree of freedom of Mn ions in phase transition as functions of temperature
and hole concentration in perovskite manganites are studied. It is shown that the orbital …

The stability of the A-type antiferromagnetic order and canted magnetic structure of LaMn O
3 perovskite is explained in the itinerant-electron picture based on the local-spin-density …

Impurity effects on charge ordering (CO) as well as magnetic ground states in perovskite-
type manganites are investigated. We found that the CO state becomes short-ranged with a …

A magnetic phase diagram of the ground state of layered perovskite manganites is studied
in a mean-field approximation for a two-orbital double exchange model with the …

In order to study nature of the electronic structures in manganites, the effective Hamiltonian
is derived by taking the degeneracy of the eg orbitals and the strong electron correlation into …

The spin, charge, and orbital ordering in R 0.5 A 0.5 MnO 3 and R 0.5 A 1.5 MnO 4 (R= rare
earth, A= Sr, Ca) has been studied by means of unrestricted Hartree-Fock calculations on …

In an A-site ordered perovskite manganite Sm 1/2 Ba 1/2 MnO 3, a new charge/orbital
ordering pattern was found at room temperature. Electron diffraction studies revealed a …