YBCO中氧原子近邻结构的温度相关性的EXAFS研究

Temperature Dependence of Local Structure Surrounding Oxygen Atoms in YBa_2Cu_3O_(7-δ) Studied by EXAFS Spectroscopy

运用定向EXAFS（E‖a）技术对高温超导材料YBa2Cu3O7－δ在不同温度下氧原子的K吸收边进行了分析，获得了材料温度从77K到105K的EXAFS信息，发现在整个温度变化过程中，O－Cu原子对的平均间距未发生改变，但表征其键长有效涨落的德拜－瓦勒因子有一个稳定的增长。

The temperature dependence of the local structure surrounding oxygen atoms in YBa2Cu3O7-δ single crystal has been investigated by orientation-dependent extended X-ray absorption fine structure spectroscopy at the O 1s edge. The analysis results show that the average O-Cu interatomic distance is independent of temperature,but the Debye-Waller factor representing the effective fluctuations of the bond length increases with temperature as the harmonic Einstein oscillator model described.