Stoichiometry dependence of the evolution of the irradiated-induced defect clusters in lanthanum-doped ceria

To study the stoichiometry dependence of irradiation e ects in fluorite-type mixed oxide nuclear fuel (UPuO2), ion implantation in La doped ceria was used. Cerium dioxide single crystals with 0 mol%, 5 mol% and 25 mol% La concentration were irradiated with 1 MeV Kr ions at 800 C. In-situ transmission electron microscope (TEM) was utilized to observe the the damage process and defects created by the ion beam irradiation. Dislocation loops were observed after irradiation and were determined to be on {111} planes, but not on {220} or {200} planes. Ab substantial difference in the average size of dislocation loops for 0 %, 5% and 25% cases was observed at several doses.The growth rate of dislocation loops and the oxygen vacancy di usivity were found to be inversely correlated.