XAS study of superconducting thin film single crystals without doping
XAS study of superconducting thin film single crystals without doping
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无掺杂超导薄膜单晶的XAS研究
DOI：
10.1117/12.915983
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
M.Naito
中科院分区：
文献类型：
--
作者：
H.Ohyanagi;A.Tsukaad;M.Naito
用偏振X射线吸收谱(XAS)对T‘-La_2CuO_4和T’-(La，Y)_2CuO_4薄膜单晶的电子态进行了研究。氧化和脱氧对近边缘结构的影响证明，这两个过程产生并消除了强烈抑制超导电性的尖端氧缺陷。近边缘谱进一步表明，脱氧是超导电性的共同前提，也会产生面内氧缺陷，不排除它对n型导电和无掺杂超导的贡献。观察到的与中子散射实验一致的局域晶格畸变可能会影响有利于未掺杂的金属态的长程磁序。
The electronic state of T'-type cuprates which exhibit superconductivity without doping was investigated by polarized x-ray absorption spectroscopy (XAS) for T'-La2CuO4and T'-(La,Y)2CuO4thin film single-crystals. The effect of oxygenation and deoxygenation on the near-edge structures evidences the two processes create and remove apical oxygen defects that strongly suppress superconductivity. The near-edge spectra further indicate that the deoxygenation, well known as a common prerequisite for superconductivity, also creates in-plane oxygen defects, whose contribution to the n-type conduction and superconductivity without doping is not ruled out. The observed local lattice distortion consistent with the neutron scattering experiment may influence a long-range magnetic order favoring a metallic state without doping.