Molecular dynamics simulations were carried out in order to understand the atomic-scale phenomena which were linked to the modifications and damage that the structure underwent during α-decay irradiation. Simulations of atomic displacement cascades over an energy range from 1 to 20keV for the initial primary knock-on atom did not show any amorphization of the structure, in agreement with what was found experimentally, and there was very little correlation between the initial orientation of the primary knock-on atom and the cascade morphology. The number of Frenkel pairs, as a function of the initial energy of the primary knock-on atom, exhibited a power-law behavior with an exponent of 0.9. This was contrary to the theoretical linear Norgett-Robinson-Torrens law. For both species, the vacancies had a tendency to aggregate and cluster near to the core of the cascade, while interstitial atoms were preferentially located at the periphery of the branches that corresponded to sub-cascades.

Molecular Dynamics Studies of Displacement Cascades in the Uranium Dioxide Matrix. L.Van Bruzel, J.M.Delaye, D.Ghaleb, M.Rarivomanantsoa: Philosophical Magazine, 2003, 83[36], 4083-101