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.
|Journal||Journal of Physics: Conference Series|
|Issue number||PART 9|
|Publication status||Published - 2008 Jan 1|
|Event||Joint 21st AIRAPT and 45th EHPRG International Conference on High Pressure Science and Technology - Catania, Italy|
Duration: 2007 Sep 17 → 2007 Sep 21
ASJC Scopus subject areas
- Physics and Astronomy(all)