X-ray powder diffraction study of the high pressure behaviour of uranium dioxide

U. Benedict , G.D. Andreetti , J.M. Fournier , A. Waintal

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.

Mots clés: ceramics; high pressure solid state phase transformations; metal insulator transition; uranium compounds; X ray diffraction examination of materials; phase transformations; UO sub 2; metal semiconductor transition; high pressure behaviour; X ray powder diffraction

Domaines: Articles anciens

U. Benedict, G.D. Andreetti, J.M. Fournier, A. Waintal. X-ray powder diffraction study of the high pressure behaviour of uranium dioxide. Journal de Physique Lettres, 1982, 43 (6), pp.171-177. ⟨10.1051/jphyslet:01982004306017100⟩. ⟨jpa-00232027⟩