Annealing of Bombardment Damage in a Diamond-Type Lattice: Theoretical

The annealing of isolated interstitial-vacancy pairs presumably introduced by bombardment is considered theoretically with special attention paid to the diamond-type lattice. It is proposed that the annealing can be divided into three stages. First, those vacancy-interstitial pairs having a small initial separation will recombine under the influence of short-range elastic forces. Second, vacancies located initially farther from their companion interstitials will wander according to a random walk process, some of them wandering back within the range of the elastic forces and recombining but some escaping from the vicinity of their interstitials. Finally, vacancies which have escaped in the second stage will continue to wander until captured on surfaces or dislocations or by interstitials other than their own. Approximate analytic expressions are derived for these various stages. An outline is given of a more complete treatment with a quantitative solution for one particular phase of the annealing in the diamond-type lattice.