Phase stability of some actinides with brannerite structure at high pressures

Journal Article · Tue Nov 15 00:00:00 EST 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.08.022· OSTI ID:21580046

Zhang, F X; Lang, M ^[1]; Zhenxian, Liu ^[2]

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1. Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)
2. Geophysical Laboratory, Carnegie Institute of Washington, DC 200015 (United States)

Structure behavior of actinide brannerites ThTi{sub 2}O{sub 6}, Y{sub 0.5}U{sub 0.5}Ti{sub 1.5}Nb{sub 0.5}O{sub 6} and their analog oxide CeTi{sub 2}O{sub 6} was studied at high pressure by using in situ x-ray diffraction, Raman scattering and infra-red absorption techniques, respectively. Brannerite structure was found to be not stable and started to become amorphous at pressures above 20 GPa. Some minor crystalline phase(s) due to phase decomposition was observed in all the three samples during pressurization. In addition, the observed bulk modulus indicated that the actinide-bearing brannerites are more compressible than their analog compound CeTi{sub 2}O{sub 6}, which may be related to the asymmetric 5f electron orbits of actinide elements. - Graphical abstract: Actinide-bearing compounds with brannerite structure and their analog CeTi{sub 2}O{sub 6} are not stable at high pressure. They were amorphized after {approx}20 GPa and a minor pressure-induced phase transition or decomposition process was always observed before amorphization. Highlights: > Phase stability of three brannerites CeTi{sub 2}O{sub 6}, ThTi{sub 2}O{sub 6}, and (U,Y)(Ti,Nb){sub 2}O{sub 6} at high pressures. > Brannerite structure was not stable and became amorphous after {approx}20 GPa. > Actinide-bearing brannerites are easier compressed than their analog compound CeTi{sub 2}O{sub 6}.

• OSTI ID: 21580046
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 11; Other Information: DOI: 10.1016/j.jssc.2011.08.022; PII: S0022-4596(11)00462-2; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION
ACTINIDES
AMORPHOUS STATE
BRANNERITE
DECOMPOSITION
OXIDES
PHASE STABILITY
PHASE TRANSFORMATIONS
PRESSURE RANGE GIGA PA
PRESSURE RANGE MEGA PA 10-100
RAMAN EFFECT
X-RAY DIFFRACTION
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
DIFFRACTION
ELEMENTS
MATERIALS
METALS
MINERALS
OXIDE MINERALS
OXYGEN COMPOUNDS
PRESSURE RANGE
PRESSURE RANGE MEGA PA
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
SCATTERING
SORPTION
STABILITY
THORIUM MINERALS
URANIUM MINERALS