Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1515719 | Journal of Physics and Chemistry of Solids | 2014 | 11 Pages |
Abstract
The Bi2(FexGa1âx)4O9 oxide solid solution possessing a mullite-type structure has been investigated by 57Fe Mössbauer spectroscopy in dependence of composition (0.1â¤xâ¤1) and temperature (293â¤T/Kâ¤1073). The spectra have been fitted with two doublets for tetrahedrally and octahedrally coordinated high-spin Fe3+ ions, respectively. The experimental areas of the subspectra were used to determine the distribution of iron on the two inequivalent structural sites. The fraction of iron cations occupying the octahedral site is found to increase with decreasing Fe content and the cation distribution is almost independent of temperature. The unusual temperature dependence of the quadrupolar splitting, QS, observed for the octahedral site with dQS/dT>0 is discussed in connexion with structural data for Bi2Fe4O9. The temperature dependence of Mössbauer isomer shifts and signal intensities is examined in the context of local vibrational properties of iron on the two inequivalent sites of the mullite-type lattice structure.
Keywords
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Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Sven-Ulf Weber, Thorsten M. Gesing, Götz Eckold, Reinhard X. Fischer, Fred-Jochen Litterst, Klaus-Dieter Becker,