Oxidation state and effective pair potential of Fe4+ ions in perovskite-type SrFeO3 annealed under high oxygen pressure

M. Okube, Y. Furukawa, A. Yoshiasa, T. Hashimoto, M. Sugahara, A. Nakatsuka

Research output: Contribution to journalConference article

6 Citations (Scopus)

Abstract

The cubic perovskite-type SrFeO3 have been obtained by annealing under high oxygen pressure of 100 MPa at 600K. X-ray absorption fine structure (XAFS) observations on Fe K-edge have been performed from 25 K to 900 K to investigate the temperature variation of the local structure and oxidation state of iron ion in the perovskite-type SrFeO3. The edge features of Fe K-edge XANES spectra and the first differential curves of XANES spectra change gradually and greatly with increasing temperature from 600k to 900K. There is no clear change near the Neel temperature. In the higher temperature region than 600 K, the threshold energy shifted to the low energy side (∼2 eV) indicating that Fe 4+ ion more reduced to Fe3+ in air. The temperature dependence of EXAFS Debye-Waller factors was investigated and harmonic effective pair potentials, V(u)= αu2/2, have been evaluated. The potential coefficients α for Fe-O, Fe-Sr and Fe-Fe distances are 6.0, 5.48 and 4.0 eV/A2, respectively.

Original languageEnglish
Article number092004
JournalJournal of Physics: Conference Series
Volume121
Issue numberPART 9
DOIs
Publication statusPublished - 2008 Jan 1
EventJoint 21st AIRAPT and 45th EHPRG International Conference on High Pressure Science and Technology - Catania, Italy
Duration: 2007 Sep 172007 Sep 21

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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