Recovery study of copper electron irradiated at 130 K by positron lifetime

Abstract

The annealing behavior of election irradiated copper was studied by means of positron lifetime. In Stage III recovery, the long-lived component appeared in the lifetime spectrum. It was attributed to the formation of three-dimensional micro voids. Therefore it is concluded that vacancies are migrating in this temperature range. The lifetime component corresponding to micro voids remains up to a rather high temperature annealing. In addition to micro voids, the existence of other kinds of defects was concluded from the detailed analysis of the lifetime data. The defects formed in Stage III disappeared at high temperature but below the temperature of annealing out of micro voids. These defects were attributed to vacancy loops. Vacancy loops were also formed through the vacancy clustering in Stage III.