Study on Effects of Pr to Site Specific Electronic Structure of High Tc Superconducting Oxide probed by soft-x-ray absorption and emission spectroscopy

软X射线吸收和发射光谱研究Pr对高温超导氧化物位点电子结构的影响

基本信息

批准号：
11640341
负责人：
YAMADA Nobuyoshi
金额：
$ 2.24万
依托单位：
The University of Electro-Communications
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640341/
关键词：
high Tc Superconductor YBa_2Cu_3O_<7-δ>PrBa_2Cu_3O_7 PrBa_2Cu_4O_8 X線吸収分光 X線発光分光

项目摘要

The site specific electronic structures of oxygen in PrBa_2Cu_3O_7 and YBa_2Cu_3O_7 compounds were recorded from the measurements of O 1 s total x-ray-fluorescence yield and O Kα x-ray fluorescence emission spectra of PrBa_2Cu_3O_7 and YBa_2Cu_3O_7 single crystals. The polarization dependence of the x-ray absorption spectra(XAS) near oxygen absorption edge in the specimens is attributed to the excitation of four in equivalent oxygen sites : O(1) chain, O (2) and O(3) in-plane, and O(4) apical oxygens and the hole states of the oxygens were specified. Thereafter, we obtained the site specific electronic structure by the O Ka x-ray emission spectra (XES), exciting the target oxygen by the use of polarization and energy dependence of hole state. The evidence of hybridization between the Pr 4f and O p-π orbital was observed in the spectrum of O(2,3) in plane of PrBa_2Cu_3O_7) which was predicted by Fehrenbacher : and Rice. The spectrum is consistent with the band theoretical calculation by Liechtenstein and Mazin, based on the Fehrenbacher and Rice model.The site specific electronic structures of oxygen in PrBa_2Cu_4O_8 and YBa_2Cu_4O_8 compounds were recorded from the measurements of O 1 s total x-ray-fluorescence yield and O Ka x-ray fluorescence emission spectra of the single crystals. Consistent results with the theory by Fehrenbacher and Rice were obtained also in these compounds

通过测量PrBa_2Cu_3O_7和YBa_2Cu_3O_7单晶的O 1 s总X射线荧光产率和O Kα X射线荧光发射光谱，记录了PrBa_2Cu_3O_7和YBa_2Cu_3O_7化合物中氧的位点特定电子结构。 - 样品中氧吸收边附近的射线吸收光谱（XAS）归因于激发四个等效氧位点：O(1) 链、O(2) 和 O(3) 平面内以及 O(4) 顶端氧和氧的空穴状态此后，我们获得了位点特异性。通过 O Ka X 射线发射光谱 (XES) 的电子结构，利用空穴态的极化和能量依赖性激发目标氧，在光谱中观察到 Pr 4f 和 O p-π 轨道之间杂化的证据。的Fehrenbacher 和 Rice 预测的 PrBa_2Cu_3O_7 平面上的 O(2,3) 谱与 Liechtenstein 和 Mazin 基于 Fehrenbacher 和 Rice 模型的能带理论计算一致。氧的位点特定电子结构。通过测量 O 1 s 总 X 射线荧光产率和 O Ka 记录 PrBa_2Cu_4O_8 和 YBa_2Cu_4O_8 化合物这些化合物的单晶X射线荧光发射光谱也得到了与Fehrenbacher和Rice的理论一致的结果。