Journal de Physique Lettres · 1982 · 54 citations · 8 references
Natural SciencesMaterials EngineeringMaterials ScienceInorganic ChemistryPhase TransformationsSolid-state ChemistryCrystal ChemistryCrystallographyElectron DiffractionPhase RelationsX-ray CrystallographyX-ray DiffractionHigh-pressure DiffractionHigh-pressure Phase BehaviorHigh-pressure Phase RelationsHigh-pressure Phase TransformationsHigh-pressure Phase TransitionsPowder DiffractionPowder Diffraction AnalysisUranium Dioxide
Uranium dioxide was studied by X-ray powder diffraction under pressure in diamond anvil cells up to 40 GPa. A gradual transition to a low symmetry high pressure phase (UO2 II) occurs in the range 29 to 38 GPa. On pressure release, UO2 II is conserved by hysteresis below 15 GPa, but retransforms completely to fcc UO2 I above 5 GPa. The transformation is likely to be a purely structural one which is not due to delocalization of 5f electrons.
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