We investigate the stability of the charge exchange (CE) phase within a microscopic model which describes a single plane as in La0.5Sr1.5MnO4. The model includes Coulomb interactions (on-site and intersite), the Jahn-Teller term and the superexchange interactions due to eg and t2g electrons. By investigating the phase diagram at T=0 in mean-field approximation we conclude that the superexchange interactions can stabilize the CE phase, but only if they are stronger than estimated from spectroscopy.
@article{arxiv.cond-mat/0303231,
title = {Jahn-Teller Effect and Superexchange in Half-Doped Manganites},
author = {Olga Sikora and Andrzej M. Oles},
journal= {arXiv preprint arXiv:cond-mat/0303231},
year = {2015}
}