Thermally Activated Point Defect Migration in Copper

Abstract

A recovery model is presented which includes specific assignments of point defect migration to the various recovery stages in copper. New experimental results showing the effects of prior cold work on the production and subsequent recovery of damage produced in copper by 10\ifmmode^\circ\else\textdegree\fi{}K and 90\ifmmode^\circ\else\textdegree\fi{}K electron irradiations are also presented. The most significant observations in these experiments are: (1) irradiation recovery Stages ${\mathrm{I}}_{D}$ and ${\mathrm{I}}_{E}$ are suppressed by previous cold work; (2) this suppression is reflected in an increased damage rate at 90\ifmmode^\circ\else\textdegree\fi{}K; (3) the additional damage which remains in Stages ${\mathrm{I}}_{D}$ and ${\mathrm{I}}_{E}$, or which is produced at 90\ifmmode^\circ\else\textdegree\fi{}K, recovers in Stage III; (4) the recovery in Stage III is altered from the bi-molecular process characteristic of annealed copper; (5) under certain conditions a super-recovery occurs in Stage III so that the measured resistivity drops below the pre-irradiation value. These observations are interpreted according to this recovery model.