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Please use this identifier to cite or link to this item: http://apo.ansto.gov.au/dspace/handle/10238/1136

Title: Zener double exchange from local valence fluctuations in magnetite.
Authors: McQueeney, RJ
Yethiraj, M
Chang, S
Montfrooij, W
Perring, TG
Honig, JM
Metcalf, P
Keywords: Temperature Range
Magnetite
Electric Conductivity
Iron
Inelastic Scattering
Spin Waves
Valence
Fluctuations
Issue Date: 14-Dec-2007
Publisher: American Physical Society
Citation: McQueeney, R. J., Yethiraj, M., Chang, S., Montfrooij, W., Perring, T. G., Honig, J. M., et al. (2007). Zener double exchange from local valence fluctuations in magnetite. Physical Review Letters, 99(24), 246401.
Abstract: Magnetite (Fe3O4) is a mixed valent system where electronic conductivity occurs on the B site (octahedral) iron sublattice of the spinel structure. Below Tv=123 K, a metal-insulator transition occurs which is argued to arise from the charge ordering of 2+ and 3+ iron valences on the B sites (Verwey transition). Inelastic neutron scattering measurements show that optical spin waves propagating on the B site sublattice (similar to 80 meV) are shifted upwards in energy above Tv due to the occurrence of B-B ferromagnetic double exchange in the mixed valent phase. The double exchange interaction affects only spin waves of Δ5 symmetry, not all modes, indicating that valence fluctuations are slow and the double exchange is constrained by short-range electron correlations above Tv. © 2007, American Physical Society
URI: http://dx.doi.org/10.1103/PhysRevLett.99.246401
http://apo.ansto.gov.au/dspace/handle/10238/1136
ISSN: 0031-9007
Appears in Collections:Journal Articles

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