STAGE I RECOVERY OF RESISTIVITY IN ELECTRON-IRRADIATED SILVER AND GOLD .I. SILVER

The stage I recovery of silver has been investigated by resistivity measurements and isochronal annealing of 99.999% purity silver after irradiation with 2.0 MeV electrons at liquid helium temperature. Detailed annealing schedules for several different initial defect concentrations and for a radiation doped run confirmed the general similarity in the stage I recovery behavior of silver and copper and revealed the systematic differences between the two metals. Silver shows several first‐order recovery substages and shows a small component of recovery due to free interstitial migration near 31 °K. The total amount of recovery in stage I was found to be a sensitive function of defect concentration, for small defect concentrations, with the amount of recovery increasing for increasing initial damage over the range investigated. The observed results are explained in terms of a “competitive process, one interstitial model” with most of stage I recovery due to close pair recombination. The fate of freely migrating interstitials is governed by the relative importance of impurity trapping, vacancy annihilation, and interstitial complex formation. The importance of each of these processes depends upon the initial defect concentration, impurity concentration, and the effectiveness of vacancies and interstitials for capturing interstitials. The higher probability of dimer formation in silver than in copper is a result of the larger radius of the interstitial strain field in silver and results in the smaller amount of stage I recovery, the smaller size of IE, and is a major contributor to the observed lack of dose dependence in silver. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim