A Theory of Magnets with Competing Double Exchange and Superexchange Interactions
Abstract
We study the competition between ferromagnetic double exchange (DE) and nearest-neighbour antiferromagnetic exchange in CMR materials. Towards this end, a single site mean field theory is proposed which emphasizes the hopping-mediated nature of the DE contribution. We find that the competition between these two exchange interactions leads to ferro- or antiferromagnetic order with incomplete saturation of the (sub)lattice magnetization. This conclusion is in contrast to previous results in the literature which find a canted spin arrangement under similar circumstances. We attribute this difference to the highly anisotropic exchange interactions used elsewhere. The associated experimental implications are discussed.
Keywords
Cite
@article{arxiv.cond-mat/9712094,
title = {A 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/9712094},
year = {2009}
}
Comments
4 pages, Latex-Revtex, 3 PostScript figures. Please see report cond-mat/9805238