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X‐ray absorption spectroscopy analysis of Ru in La2RuO5
Authors:Iztok Arčon  Andreja Benčan  Alojz Kodre  Marija Kosec
Institution:1. University of Nova Gorica, Vipavska 13, SI‐5000 Nova Gorica, Slovenia;2. Jo?ef Stefan Institute, Jamova 39, SI‐1000 Ljubljana, SloveniaUniversity of Nova Gorica, Vipavska 13, SI‐5000 Nova Gorica, Slovenia.;3. Jo?ef Stefan Institute, Jamova 39, SI‐1000 Ljubljana, Slovenia;4. Faculty of Mathematics and Physics, University of Ljubljana, Slovenia
Abstract:The compound La2RuO5 was examined by the x‐ray absorption spectroscopy (XAS) methods, x‐ray absorption near edge structure (XANES) and extended x‐ray absorption fine structure (EXAFS). XANES technique was used to probe directly the average valence of Ru atoms in the compound. The energy shift of the Ru K‐edge in the XANES signal gave the average Ru valence state as 4.0 ± 0.1. EXAFS analysis provided, by yielding directly the interatomic distances and coordination numbers, the first information on the Ru atom neighborhood, on which the model for the Rietveld refinement of the unit cell of the new compound was devised. Finally, the local structure around the Ru atoms from the refinement was used in the FEFF6 code for a model EXAFS spectrum. The very good quantitative agreement with the measured spectrum proves that the refined crystal structure contains no systematic defects in the vicinity of Ru atoms. This result, together with the valence obtained from XANES, strongly confirms the proposed La2RuO5 stoichiometry. Copyright © 2007 John Wiley & Sons, Ltd.
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