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Theory of High-Energy Spectroscopy in f and d Electron Systems

f 和 d 电子系统中的高能谱理论

基本信息

批准号：
63540268
负责人：
KOTANI Akio
金额：
$ 1.22万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

1. A new theory is formulated and its computer program is prepared for high-energy spectroscopy of f and d electron systems by incorporating the intra-atomic multiplet coupling into the mier-atomic charge transfer effect as an extension of the impurity Anderson model. The theory is applied to the analysis of the rare-earth 3d and 4d X-ray absorption spectra (XAS) of CeO_2 and PrO_2, by which a long-standing controversy on the interpretation of multiplet structures in these spectra is solved successfully. Multiplet structures in X-ray photoemission spectra (XPS) of rare-earth compounds and high-T_c, superconductors are also analyzed. Especially, the first theoretical prediction is given on the polarization-dependent XPS in strongly anisotropic systems such as high-T_c, superconductors.2. A systematic analysis is carried out for XPS of rare-earth oxides R_2O_3 (R=La - Yb), RO_2 (R=Ce,Pr,Tb) and actinide oxides AO_2 (A=Th - Cm). X-ray magnetic dichroism is also calculated for actinide atoms in a magnetic field.3. X-ray emission spectra (XES) associated with rare-earth 4f->3d, 5p->3d and 3d->2p electronic transitions are calculated for rare-earth compounds LaF_3, CeF_3 and CeO_2 by using a formula of the second-order optical process. The importance of the quantum mechanical interference effect is pointed out.4. XAS, XPS and XES in high-T_c superconductors are analyzed with the impurity Anderson model, and the key parameters describing the electronic states are estimated. The site and the symmetry of extra-holes doped in YBaCuO systems are studied from the analysis of the polarization dependence of Cu 2p and O 1s XAS.

1.将原子内多重态耦合引入到混合原子电荷转移效应中，作为杂质Anderson模型的推广，建立了f和d电子体系高能谱的新理论，并编制了相应的计算程序。将该理论应用于CeO_2和Pro_2的稀土三维和四维X射线吸收谱的分析，成功地解决了长期以来对这些谱中多重态结构解释的争论。分析了稀土化合物和高T_c超导体的X射线光电子能谱(XPS)中的多重态结构。特别是首次对高T_c超导体等强各向异性体系中的偏振相关XPS进行了理论预测。本文系统地分析了稀土氧化物R_2O_3(R=La-Yb)、RO_2(R=Ce、Pr、Tb)和鳗系氧化物O_2(A=Th-Cm)的XPS。此外，还计算了在磁场中鳗系元素原子的X射线磁二向色性。用二级光学过程公式计算了稀土化合物LaF_3、CeF_3和CeO_2的4f-&gt；3d、5p-gt；3d和3d-gt；2p电子跃迁的X射线发射光谱。指出了量子力学干涉效应的重要性。用杂质Anderson模型分析了高T_c超导体的XAS、XPS和XES，并估算了描述电子态的关键参数。通过分析Cu2p和O1SxAs的偏振特性，研究了YBaCuO系统中额外空穴掺杂的位置和对称性。