Probing magnetic order in EELS of chromite spinels using both multiple scattering (FEFF8.2) and DFT (WIEN2k)

Eustace, D.A., McComb, D.W. and Craven, A.J. (2010) Probing magnetic order in EELS of chromite spinels using both multiple scattering (FEFF8.2) and DFT (WIEN2k). Micron, 41(6), pp. 547-553. (doi: 10.1016/j.micron.2010.04.013)

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The electron energy loss near edge structure on the O K-edge from chromite spinels contains fine structure from the hybridisation of the O p-orbitals and the Cr d-orbitals. Unlike the aluminates, a non-spin polarised calculation of this fine structure differs significantly from experimental observations. This is due to the large magnetic moment on the Cr. Calculations using simplified collinear ordering of the spins and the local spin density approximation give much improved agreement. A real space multiple scattering formalism and a reciprocal space density functional formalism give results in substantial agreement. In general, the actual spin arrangement of these chromites is not known since they are typically frustrated magnetic systems with ordering temperatures in the 10–20 K range. The calculations are based on the hypothesis that dynamic short range order persists to room temperature over the time scale of the interaction with the fast electron. However, it is possible that the observed effects are due to the strong paramagnetism present at room temperatures but which it is not possible to simulate accurately at present.

Item Type:Articles
Keywords:ELNES, chromite spinels, magnetic order, local spin density approximation, FEFF8.2, WIEN2k
Glasgow Author(s) Enlighten ID:Craven, Professor Alan
Authors: Eustace, D.A., McComb, D.W., and Craven, A.J.
Subjects:Q Science > QC Physics
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Micron
ISSN (Online):1878-4291
Published Online:30 April 2010
Copyright Holders:Copyright © 2010 Elsevier
First Published:First published in Micron 41(6):547-553
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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