- 作者: 劉如熹,詹丁山,張凌雲
- 作者服務機構: Department of Chemistry and Center for Nano Storage Research, National Taiwan University, Taipei 106, Taiwan, R.O.C.
- 中文摘要: The local structure of the double perovskite (Sr2-xCax)FeMoO6 (0 £ x £ 2.0) and Sr2CrMO6 (M = Mo, W) systems have been probed by extended X-ray absorption fine structure (EXAFS) spectroscopy at the Fe and Cr K-edges. We found Fe-O (ave) distance apparently decreases from 1.999 A (x = 0) to 1.991 A (x = 1.0) in (Sr2-xCax)FeMoO6 (tetragonal structure). When x is increased further from 1.5 to 2.0, the Fe-O bond distance decreased from 2.034 A to 2.012 A (monoclinic structure). In addition, Cr-O, Sr-Cr, and Cr-Mo bond distances in Sr2CrWO6 are all slightly larger than the bond distances of Sr2CrMoO6, which is due to the ionic radius of the W5+ (0.62 A) which is larger than the ionic radius of Mo5+ (0.61 A). The results are consistent with our XRD refinements data.
- 英文摘要: --
- 中文關鍵字: Double perovskites; X-ray absorption spectroscopy; EXAFS.
- 英文關鍵字: --