Use of HERFD–XANES at the U L3- and M4-Edges ...
Document type :
Article dans une revue scientifique
Permalink :
Title :
Use of HERFD–XANES at the U L3- and M4-Edges To Determine the Uranium Valence State on [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3]
Author(s) :
Bès, René [Auteur]
Rivenet, Murielle [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Solari, Pier-Lorenzo [Auteur]
Kvashnina, Kristina O. [Auteur]
Scheinost, Andreas C. [Auteur]
Martin, Philippe M. [Auteur]
Rivenet, Murielle [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Solari, Pier-Lorenzo [Auteur]
Kvashnina, Kristina O. [Auteur]
Scheinost, Andreas C. [Auteur]
Martin, Philippe M. [Auteur]
Journal title :
Inorganic Chemistry
Volume number :
55
Pages :
4260-4270
Publication date :
2016-04-13
HAL domain(s) :
Chimie/Matériaux
English abstract : [en]
We report and discuss here the unambiguous uranium valence state determination on the complex compound [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3] by using high-energy-resolution fluorescence detection–X-ray absorption near-edge ...
Show more >We report and discuss here the unambiguous uranium valence state determination on the complex compound [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3] by using high-energy-resolution fluorescence detection–X-ray absorption near-edge structure spectroscopy (HERFD–XANES). The spectra at both U L3- and M4-edges confirm that all five nonequivalent U atoms are solely in the hexavalent form in this compound, as previously suggested by bond-valence-sum analysis and X-ray diffraction pattern refinement. Moreover, the presence of the preedge feature, due to the 2p3/2–5f quadrupole transition, has been observed in the U L3-edge HERFD–XANES spectrum, in agreement with theoretical and experimental observations of other uranium-based compounds. Recently, this feature has been proposed as a possible tool to determine the uranium oxidation state in a manner similar to that of 3d and 4d metals. Nevertheless, this feature is also very sensitive to the uranium local environment, as revealed by our theoretical calculations, and consequently could not be used to attribute without ambiguity the uranium valence state. In contrast, U M4-edge HERFD–XANES appears to be the most straightforward and reliable way to assess the uranium valence state in very complex materials such as [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3] or a mixture of compounds.Show less >
Show more >We report and discuss here the unambiguous uranium valence state determination on the complex compound [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3] by using high-energy-resolution fluorescence detection–X-ray absorption near-edge structure spectroscopy (HERFD–XANES). The spectra at both U L3- and M4-edges confirm that all five nonequivalent U atoms are solely in the hexavalent form in this compound, as previously suggested by bond-valence-sum analysis and X-ray diffraction pattern refinement. Moreover, the presence of the preedge feature, due to the 2p3/2–5f quadrupole transition, has been observed in the U L3-edge HERFD–XANES spectrum, in agreement with theoretical and experimental observations of other uranium-based compounds. Recently, this feature has been proposed as a possible tool to determine the uranium oxidation state in a manner similar to that of 3d and 4d metals. Nevertheless, this feature is also very sensitive to the uranium local environment, as revealed by our theoretical calculations, and consequently could not be used to attribute without ambiguity the uranium valence state. In contrast, U M4-edge HERFD–XANES appears to be the most straightforward and reliable way to assess the uranium valence state in very complex materials such as [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3] or a mixture of compounds.Show less >
Language :
Anglais
Audience :
Internationale
Popular science :
Non
Administrative institution(s) :
ENSCL
CNRS
Centrale Lille
Univ. Artois
Université de Lille
CNRS
Centrale Lille
Univ. Artois
Université de Lille
Collections :
Research team(s) :
Chimie du solide et matériaux du nucléaire
Chimie, matériaux et procédés pour un nucléaire durable (CIMEND)
Chimie, matériaux et procédés pour un nucléaire durable (CIMEND)
Submission date :
2019-09-25T14:04:44Z