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On the Theory of Magnets with Competing Double Exchange and Superexchange Interactions

D. I. Golosov·M. R. Norman·K. Levin
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Abstract

In the CMR materials, ferromagnetic double exchange (DE) presumably coexists with a direct nearest-neighbour antiferromagnetic interaction. We construct a single-site mean field theory that explicitly takes into account the different nature of carrier-mediated ferromagnetism vs. Heisenberg-like superexchange. We find, in contrast to previous results in the literature, that the competition between these two exchange interactions leads to ferro- or antiferromagnetic order with incomplete saturation of the magnetization (or sublattice magnetization), rather than spin canting. The associated experimental implications are discussed.

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D. I. Golosov, M. R. Norman, K. Levin. 1998-07-24. On the Theory of Magnets with Competing Double Exchange and Superexchange Interactions. https://doi.org/10.1103/physrevb.58.8617

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