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Phase separation in systems with charge ordering

M. Yu. Kagan·K. I. Kugel·D. I. Khomskii
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Abstract

A simple model of charge ordering is considered. It is shown explicitly that at any deviation from half-filling ($n \neq 1/2$) the system is unstable with respect to phase separation into charge ordered regions with $n = 1/2$ and metallic regions with smaller electron or hole density. Possible structure of this phase-separated state (metallic droplets in a charge-ordered matrix)is discussed. The model is extended to account for the strong Hund-rule onsite coupling and the weaker intersite antiferromagnetic exchange. An analysis of this extended model allows us to determine the magnetic structure of the phase-separated state and to reveal the characteristic features of manganites and other substances with charge ordering.

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M. Yu. Kagan, K. I. Kugel, D. I. Khomskii. 2000-05-19. Phase separation in systems with charge ordering. https://doi.org/10.1134/1.1402742

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