镧掺杂氧化铀中五价铀的化学键特征
Characteristics of chemical bonding of pentavalent uranium in La-doped UO.
作者信息
Butorin Sergei M, Kvashnina Kristina O, Prieur Damien, Rivenet Murielle, Martin Philippe M
机构信息
Molecular and Condensed Matter Physics, Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden.
The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France and Helmholtz Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology, P.O. Box 510119, 01314, Dresden, Germany.
出版信息
Chem Commun (Camb). 2016 Dec 20;53(1):115-118. doi: 10.1039/c6cc07684j.
The effect of La doping on the electronic structure of U in UO was studied using an advanced technique, namely, X-ray absorption spectroscopy (XAS) in the high-energy-resolution fluorescence-detection (HERFD) mode, at the U 3d (M) edge. Thanks to a significant reduction of the core-hole lifetime broadening and distinct chemical shifts of the HERFD-XAS lines, the U(v) formation as a result of La doping was identified. The isolated contribution of U(v) in the M HERFD-XAS spectrum reveals the so-called charge-transfer satellites due to the U 5f-O 2p hybridization. The analysis of the experimental data within the framework of the Anderson impurity model (AIM) indicates a significant change in the characteristics and degree of covalency for the chemical bonding in the U(v) subsystem of UO as compared to undoped UO, which is a Mott-Hubbard system. The results are also supported by AIM calculations of X-ray photoelectron and optical absorption data.
利用一种先进技术，即在高能分辨荧光检测（HERFD）模式下的X射线吸收光谱（XAS），在U 3d（M）边缘研究了La掺杂对UO中U电子结构的影响。由于芯孔寿命展宽的显著降低以及HERFD-XAS谱线明显的化学位移，确定了La掺杂导致U（v）的形成。M HERFD-XAS光谱中U（v）的孤立贡献揭示了由于U 5f-O 2p杂化产生的所谓电荷转移卫星峰。在安德森杂质模型（AIM）框架内对实验数据的分析表明，与未掺杂的UO（一种莫特-哈伯德体系）相比，UO的U（v）子系统中化学键的特征和共价程度发生了显著变化。X射线光电子和光吸收数据的AIM计算结果也支持了这些结果。
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