Sensitivity to Actinide Doping of Uranium Compounds by Resonant Inelastic X-ray Scattering at Uranium L-3 Edge
2015 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 87, no 17, 8772-8780 p.Article in journal (Refereed) Published
Valence-to-core resonant inelastic X-ray scattering (RIXS) and high energy resolution fluorescence detection (HERFD) X-ray absorption measurements were performed at the U (L)3 edges of UO2 and UO2(NO3)(2)(H2O)(6). The results are compared with model calculations based on the local-density-approximation formalism, taking into account Coulomb interaction U (LDA + U). We show that despite strong 5f-5f electronic correlations in the studied systems and the use of core-level excitations in the intermediate stage of the spectroscopic process, the RIXS technique probes a convolution of the single-particle densities of states in the valence and conduction bands. For UO2, the detected crystal-field splitting between the U 6d e(g) and t(2g) orbitals from the RIXS spectra (similar to 3.5 eV) is larger than that previously derived from optical spectroscopy. Furthermore, by using an example of the U0.75Pu0.25O2 mixed oxide, we show that the RIXS technique at the U L-3 edges is sensitive to the substitution of U with other actinide, in contrast to conventional X-ray absorption methods. That is, due to changes in the occupied part rather than in the unoccupied part of the U 6d states caused by the substitution.
Place, publisher, year, edition, pages
2015. Vol. 87, no 17, 8772-8780 p.
IdentifiersURN: urn:nbn:se:uu:diva-264057DOI: 10.1021/acs.analchem5b01699ISI: 000360773100027PubMedID: 26255719OAI: oai:DiVA.org:uu-264057DiVA: diva2:858975