Point defect concentration development in electron-irradiated bucky onions

Abstract

Rate equations for the generation and recombination of vacancies and selfinterstitial atoms in a spherical bucky onion under electron irradiation are proposed. They are used to study the temporal development of the point defect concentrations in different shells of onions. The self-interstitial concentration was found to remain low and to be only slightly enriched near the onion centre. The loss of atoms from the outer surface of the bucky onions by sputtering acts as a vacancy source for the whole onion. Irradiation-induced diffusion leads to a net flux of vacancies towards the onion core. The coupling between neighbouring shells necessary for this radial diffusion can be described by the concept of intermediate shells introduced here.