Effects of non-magnetic doping upon orbital and magnetic structures of lanthanum manganite

Abstract

The theoretical model of the crystal structure of lanthanum manganite doped by non- Jahn-Teller ions is proposed. In order to describe the changes in the crystal structure and orbital state of manganese ions subsystem, we use modified shell model and virtual crystal model. The orbital ordering collapse is explained in terms of dynamical Jahn-Teller effect. The model of superexchange interaction helps to find the values of antiferromagnetic and ferromagnetic exchange parameters for dynamical and static orbital states of interacting ions. The magnetic structure of LaMn1-xGaxO3 is explained and magnetic resonance spectrum is predicted. © (2012) Trans Tech Publications.