High-voltage transmission electron microscopy was used to examine the formation of dislocation loops as a function of incident electron energy to reveal the formation of defects and kinetics in CeO2. In the case of electron irradiation methods with an energy range from 200 to 1250keV, interstitial-type non-stoichiometric dislocation loops of the 1/9<111>{111} type were formed by the aggregation of O ions. In contrast, interstitial-type perfect dislocation loops of the 1/2<110>{110} type were formed with electron irradiations with an energy range from 1500 to 3000keV. The formation of perfect dislocation loops induced by incident electrons above 1500keV indicated the displacement of both constituent ions with elastic collisions of electrons. Based on the findings of the formation and growth behavior of each interstitial-type dislocation loop caused by different displacement conditions, the threshold displacement energies of the sub-lattices and the migration energy of the Ce vacancy in CeO2 were estimated.

Electron Energy-Dependent Formation of Dislocation Loops in CeO2. K.Yasunaga, K.Yasuda, S.Matsumura, T.Sonoda: Nuclear Instruments and Methods in Physics Research B, 2008, 266[12-13], 2877-81