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Orbital Ordering in Paramagnetic LaMnO3 and KCuF3

J. E. Medvedeva·M. A. Korotin·V. I. Anisimov·A. J. Freeman
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Abstract

{\it Ab-initio} studies of the stability of orbital ordering, its coupling to magnetic structure and its possible origins (electron-phonon and/or electron-electron interactions) are reported for two perovskite systems, LaMnO$_3$ and KCuF$_3$. We present a new Average Spin State (ASS) calculational scheme that allowed us to treat a paramagnetic state. Using this scheme, we succesfully described the experimental magnetic/orbital phase diagram of both LaMnO$_3$ and KCuF$_3$ in crystal structures when the Jahn-Teller distortions are neglected. Hence, we conclude that the orbital ordering in both compounds is purely electronic in origin.

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J. E. Medvedeva, M. A. Korotin, V. I. Anisimov, A. J. Freeman. 2002-03-15. Orbital Ordering in Paramagnetic LaMnO3 and KCuF3. https://doi.org/10.1103/physrevb.65.172413

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