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Persistent URL http://purl.org/net/epubs/work/50905981
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Record Id 50905981
Title Synthesis, Characterization, and Crystal Structure of Dominant Uranium(V) Brannerites in the UTi2–xAlxO6 System
Abstract The synthesis, characterization, and crystal structure of a novel (dominant) uranium(V) brannerite of composition U1.09(6)Ti1.29(3)Al0.71(3)O6 is reported, as determined from Rietveld analysis of the high-resolution neutron powder diffraction data. Examination of the UTi2–xAlxO6 system demonstrated the formation of brannerite-structured compounds with varying Al3+ and U5+ contents, from U0.93(6)Ti1.64(3)Al0.36(3)O6 to U0.89(6)Ti1.00(3)Al1.00(3)O6. Substitution of Al3+ for Ti4+, with U5+ charge compensation, resulted in near-linear changes in the b and c unit cell parameters and the overall unit cell volume, as expected from ionic radii considerations. The presence of U5+ as the dominant oxidation state in near-single-phase brannerite compositions was evidenced by complementary laboratory U L3-edge and high-energy-resolution fluorescence-detected U M4-edge X-ray absorption near-edge spectroscopy. No brannerite phase was found for compositions with Al3+/Ti4+ > 1, which would require a U6+ contribution for charge compensation. These data expand the crystal chemistry of uranium brannerites to the stabilization of dominant uranium(V) brannerites by the substitution of trivalent cations, such as Al3+, on the Ti4+ site.
Organisation ISIS , ISIS-HRPD , STFC
Funding Information EPSRC (EP/N017374/1); EPSRC (EP/S01019X/1); EPSRC (EP/T011424/1); ERC, H2020 (759696)
Related Research Object(s): 10.5286/ISIS.E.RB2000257
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Language English (EN)
Type Details URI(s) Local file(s) Year
Journal Article Inorg Chem 60, no. 23 (2021): 18112-18121. doi:10.1021/acs.inorgchem.1c02733 2021