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

1.作为杂质安德森模型的推广，将原子内多重态耦合引入到原子间电荷转移效应中，建立了f和d电子系统的高能谱理论，并编制了相应的计算机程序。应用该理论分析了CeO_2和PrO_2的3d和4d X射线吸收谱（XAS），成功地解决了对这些谱中多重态结构解释的长期争论。本文还分析了稀土化合物和高温超导体的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的极化相关XPS进行了理论预测.本文对稀土氧化物R_2O_3（R= La-Yb），RO_2（R=Ce，Pr，Tb）和锕系氧化物AO_2（A= Th-Cm）的XPS进行了系统的分析。还计算了磁场中锕系元素原子的X射线磁二向色性.本文用二级光学过程公式计算了LaF_3，CeF_3，CeO_2的4f->3d，5 p->3d和3d-> 2 p电子跃迁的X射线发射谱。指出了量子力学干涉效应的重要性.本文用杂质安德森模型分析了高温超导体的XAS、XPS和XES，并估算了描述电子态的关键参数。从Cu 2 p和O 1 sXAS的极化依赖关系出发，研究了YBaCuO体系中额外空穴的掺杂位置和对称性.

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.