Iron orbital occupancies upon valence mixing of charge-ordered GdBaFeIIFeIIIO5

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: J. Lindén, F. Lindroos, P. Karen
Editors: Guido Langouche
Publication year: 2014
Journal: Hyperfine Interactions
Publisher: Springer
Book title: Proceedings of the 32nd International Conference on the Applications of the Mössbauer Effect (ICAME 2013) held in Opatija, Croatia, 1-6 September 2013
Number in series: 1-3
Volume number: 226
Start page: 329
End page: 339
ISSN: 0304-3843


Abstract

Mössbauer spectra of charge-ordered/valence-mixed GdBaFe2O5 have been analyzed in order to determine the orbital occupancies of the minority-spin d electron as a function of temperature. In the charge-ordered state below the Verwey temperature TV, it occupies the Fe2+ dxz orbital, which is ordered. Above TV, the electron partially occurs also at the trivalent iron and spreads over two additional orbitals, dx2-y2 and dz2. In the valence-mixing state (above Tp) also orbital dyz participates. The study illustrates how the Mössbauer electric-field gradient, center shift and internal field jointly reflect the distribution of the minority-spin electron culprit behind the Verwey transition.


Keywords

57Fe Mössbauer spectroscopy, Charge ordering, Double perovskites, Mixed valence, Valence mixing

Last updated on 2019-15-10 at 02:31