Uranium-Induced Changes in Crystal-Field and Covalency Effects of Th4+ in Th1- x U x O2 Mixed Oxides Probed by High-Resolution X-ray Absorption Spectroscopy

Inorganic Chemistry
Hongliang BaoJian-Qiang Wang

Abstract

Knowledge of the local Th structure is a prerequisite for a better understanding of the physicochemical properties of the thorium-based mixed oxides (Th-MOX) involved in the Th-based nuclear fuel cycle. The crystalline electric field (CEF) splitting of the 6d shell in Th1- xU xO2 ( x = 0.25, 0.5, 0.75) solid solution was probed by the Th L3 edge high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) collected at the Lβ5 emission line, which cannot be obtained by conventional X-ray absorption methods. The detected CEF split between the 6d eg and t2g orbitals in ThO2 consisting of ordered Th-O8 cubes with cubic symmetry is ∼3.5 eV for the Th4+ ion. Because the split peaks of the white line corresponding to the crystal-field splitting of the unoccupied 6d states were resolved in the HERFD-XANES spectra, the analysis of these split peaks combined with first-principles calculations revealed that an increase of the U content involves the distortion of the Th-O8 cubes in the Th1- xU xO2 mixed oxides. The lower symmetry of the Th-O8 cube induced by the incorporated U tends to reduce the local crystal-field around Th4+ as well as the hybridization of Th 6t2g-O 2p which is mainly responsible ...Continue Reading

References

Mar 15, 1991·Physical Review. B, Condensed Matter·D Singh
Aug 1, 1992·Physical Review. B, Condensed Matter·L TrögerE Zschech
Nov 11, 1991·Physical Review Letters·K HämäläinenL E Berman
Oct 27, 2004·Inorganic Chemistry·Steven D ConradsonVincenzo V Rondinella
Jun 22, 2005·Journal of Synchrotron Radiation·B Ravel, M Newville
May 7, 2010·Physical Chemistry Chemical Physics : PCCP·John J RehrKevin Jorissen
Oct 27, 2011·Inorganic Chemistry·Laurent ClaparedePhilippe Moisy
Feb 28, 2013·Inorganic Chemistry·Renaud C BelinAndreas C Scheinost
Feb 4, 2014·Physical Review Letters·K O KvashninaP Glatzel
Aug 30, 2014·Advanced Materials·Wei-Qun ShiZhi-Fang Chai
May 4, 2016·Journal of Synchrotron Radiation·Kristina O Kvashnina, Andreas C Scheinost
Jun 4, 2016·Chemistry : a European Journal·Sergei M ButorinPhilippe M Martin
Jul 3, 2016·Proceedings of the National Academy of Sciences of the United States of America·Sergei M ButorinDavid K Shuh

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Citations

May 14, 2019·Physical Chemistry Chemical Physics : PCCP·Lucia AmidaniKristina O Kvashnina

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