Title: Crystal-field and covalency effects in uranates: An X-ray spectroscopic study
Authors: BUTORIN S. M.KVASHNINA KristinaSMITH AnnaPOPA KARINMARTIN Philippe
Citation: CHEMISTRY-A EUROPEAN JOURNAL vol. 22 no. 28 p. 9693-9698
Publisher: WILEY-V C H VERLAG GMBH
Publication Year: 2016
JRC N°: JRC98569
ISSN: 0947-6539
URI: http://publications.jrc.ec.europa.eu/repository/handle/JRC98569
DOI: 10.1002/chem.201505091
Type: Articles in periodicals and books
Abstract: The electronic structure of U(V)- and U(VI)-containing uranates NaUO3 and Pb3UO6 was studied by using an advanced technique, namely X-ray absorption spectroscopy (XAS) in high-energy-resolution fluorescence-detection (HERFD) mode. Due to a significant reduction in core-hole lifetime broadening, the crystal-field splittings of the 5f shell were probed directly in HERFD-XAS spectra collected at the U3d edge, which is not possible by using conventional XAS. In addition, the charge-transfer satellites that result from U5f–O2p hybridization were clearly resolved. The crystal field parameters, 5f occupancy, and degree of covalency of the chemical bonding in these uranates were estimated by using the Anderson impurity model by calculating the U3d HERFD-XAS, conventional XAS, core-to-core (U 4f–3d transitions) resonant inelastic X-ray scattering (RIXS), and U4f Xray photoelectron spectra. The crystal field was found to be strong in these systems and the 5f occupancy was determined to be 1.32 and 0.84 electrons in the ground state for NaUO3 and Pb3UO6, respectively, which indicates a significant covalent character for these compounds.
JRC Directorate:Nuclear Safety and Security

Files in This Item:
There are no files associated with this item.


Items in repository are protected by copyright, with all rights reserved, unless otherwise indicated.