Low-temperature lattice structure anomaly in the LaFeAsO0.93F0.07 superconductor by x-ray absorption spectroscopy: Evidence for a strong electron-phonon interaction
Low-temperature lattice structure anomaly in the LaFeAsO0.93F0.07 superconductor by x-ray absorption spectroscopy: Evidence for a strong electron-phonon interaction
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DOI：
10.1103/physrevb.78.214513
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发表时间：
2008-12-01
影响因子：
3.7
通讯作者：
Hosono, H.
中科院分区：
文献类型：
--
作者：
Zhang, C. J.;Oyanagi, H.;Hosono, H.
用扩展的X射线吸收精细结构测量研究了LaFeAsO_（1-x）Fx超导体的局域晶格结构。当温度低于70 K时，随着电子载流子的引入，Fe-As键的均方相对位移出现了异常的上升，反映了Fe-As键局域晶格涨落的发生。与铜酸盐类似，这种晶格涨落在超导转变温度开始时表现出突然的下降。结果表明，强的电子-晶格相互作用参与了氧铌酸盐超导体的超导转变，严格限制了可能的理论模型。
The local lattice structure in LaFeAsO1-xFx superconductors is studied by extended x-ray absorption fine-structure measurements. An anomalous upturn of the mean-square relative displacement of the Fe-As bond is detected below similar to 70 K as electron carriers are introduced, reflecting the occurrence of Fe-As bond local lattice fluctuation. Similar to that in cuprates, this lattice fluctuation exhibits an abrupt depression at the onset superconducting transition temperature. The results indicate that strong electron-lattice interaction is involved in the superconducting transition in oxypcnictide superconductors, putting a strict limitation on possible theoretical models.