On the Theory of Magnets with Competing Double Exchange and Superexchange Interactions
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.
Keywords
Cite
@article{arxiv.cond-mat/9805238,
title = {On the Theory of Magnets with Competing Double Exchange and Superexchange Interactions},
author = {D. I. Golosov and M. R. Norman and K. Levin},
journal= {arXiv preprint arXiv:cond-mat/9805238},
year = {2009}
}
Comments
This is a long version of an earlier paper, cond-mat/9712094. 10 pages, Latex-Revtex, 8 PostScript figures. Minor revisions, references added