XAS characterisation of xenon bubbles in uranium dioxide

P. Martin (1) , P. Garcia (1) , G. Carlot (1) , C. Sabathier (1) , C. Valot (1) , V. Nassif (2) , O. Proux (3) , J.-L. Hazemann (4)

1 LM2C - Laboratoire de Modélisation Multi-échelles des Combustibles
2 NRS - Nanostructures et Rayonnement Synchrotron
3 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
4 NEEL - MRS - Matériaux, Rayonnements, Structure

X-ray absorption spectroscopy experiments were performed on a set of uranium dioxide samples implanted with 1017 xenon cm−2 at 800 keV (8 at.% at 140 nm). EXAFS measurements performed at 12 K showed that during implantation the gas forms highly pressurised nanometre size inclusions. Bubble pressures were estimated at 2.8 ± 0.3 GPa at low temperature. Following the low energy xenon implantation, samples were annealed between 1073 and 1773 K for several hours. Stability of nanometre size highly pressurized xenon aggregates in UO2 is demonstrated up to 1073 K as for this temperature almost no modification of the xenon environment was observed. Above this temperature, bubbles will trap migrating vacancies and their inner pressure is seen to decrease substantially.

Domaines: Matériaux; Science des matériaux [cond-mat.mtrl-sci]; Cristallographie

P. Martin, P. Garcia, G. Carlot, C. Sabathier, C. Valot, et al.. XAS characterisation of xenon bubbles in uranium dioxide. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2008, 266 (12-13), pp.2887 - 2891. ⟨10.1016/j.nimb.2008.03.180⟩. ⟨hal-01874667⟩