PACS 62.20.Dc, 63.20.Dj, 71.70.Ej, 75.25.+z, 75.30.Et Within the framework of strong electron-lattice interaction of Mn 3+ ions and orbital dependent exchange interaction model, the crystal and magnetic structures of charge ordered phase La 1/3 Ca 2/3 MnO3 are studied. The calculation results are in agreement with the "Wigner crystal" model. The estimated superexchange parameters confirm the qualitative conclusions of experimental works about frustrated magnetic structure with magnetic supercell (3a × b × 2c). The values of hyperfine magnetic fields on 55 Mn nuclei in different charge states in charge ordering phase are calculated.
Introduction A noticeable interest to investigation of manganites Laproperties is caused by discovery of colossal magnetoresistance effect in these compounds. Mentioned materials have also a number of nontrivial properties shown of various concentrations of an alkaline-earth impurity. One of such properties is the charge ordering (CO). The CO phase arises at doping of crystal by a non-isovalvent impurity at some temperature. In this phase, free charge carriers are localized and form the superstructure. In manganites, this localization causes an alternation of magnetic ions Mn 3+ /Mn 4+ . The phenomenon of CO is interesting because there is a necessity for taking into account all aspects of manganite's physics (localization of charges, structural distortions, orbital ordering, and magnetic interactions).The new phases of crystal, orbital, charge, and magnetic structures are recently discovered in 2/3 Cadoped manganites [1][2][3]. The observed CO structure is described in the paper [1] by the bistripe model, and in the papers [2,3] it is described by the single-stripe model, called also a "Wigner crystal" model.In the current work, we introduce an investigation of charge, orbital, and magnetic structures of the crystal La 1/3 Ca 2/3 MnO 3 within the framework of the models of strong electron-lattice interaction and orbital-dependent exchange-interaction [4,5].