Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf
1 PublikationA multimodal X-ray spectroscopy investigation of uranium speciation in ThTi2O6 compounds with the brannerite structure
Dixon Wilkins, M. C.; Townsend, L. T.; Stennett, M. C.; Kvashnina, K.; Corkhill, C. L.; Hyatt, N. C.
Abstract
ThTi2O6 derived compounds with the brannerite structure were designed, synthesised, and characterised with the aim of stabilising incorporation of U5+ or U6+, at dilute concentration. Appropriate charge compensation was targeted by co-substitution of Gd3+, Ca2+, Al3+, or Cr3+, on the Th or Ti site. U L3 edge X-ray Absorption Near Edge Spectroscopy (XANES) and High Energy Resolution Fluorescence Detected U M4 edge XANES evidenced U5+ as the major oxidation state in all compounds, with a minor fraction of U6+ (2–13%). The balance of X-ray and Raman spectroscopy data support uranate, rather than uranyl, as the dominant U6+ speciation in the reported brannerites. It is considered that the U6+ concentration was limited by unfavourable electrostatic repulsion arising from substitution in the octahedral Th or Ti sites, which share two or three edges, respectively, with neighbouring polyhedra in the brannerite structure.
Beteiligte Forschungsanlagen
- Rossendorf Beamline an der ESRF DOI: 10.1107/S1600577520014265
Verknüpfte Publikationen
- DOI: 10.1107/S1600577520014265 is cited by this (Id 37509) publication
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Scientific Reports 13(2023), 12776
DOI: 10.1038/s41598-023-38912-1
Cited 2 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-37509