Low-Temperature Annealing Spectrum of Electron-Irradiated Gold and Cadmium

Abstract

Cadmium and gold of 99.999% purity were irradiated to an integrated flux of 7.5\ifmmode\times\else\texttimes\fi{}${10}^{17}$ electrons/${\mathrm{cm}}^{2}$ using 3-MeV electrons. The resistivity increase was 8.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}9}$ \ensuremath{\Omega}-cm in gold and 2.32\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}9}$ \ensuremath{\Omega}-cm in cadmium. The resistivity versus integrated flux curve is linear. Isothermal annealing measurements were made in the region from 8 to 51\ifmmode^\circ\else\textdegree\fi{}K. The resistivity annealing spectrum of gold was derived directly from the isothermal annealing curves. The spectrum consists of at least nine peaks, with 22% of the damage annealing out up to 51\ifmmode^\circ\else\textdegree\fi{}K. These results confirm earlier suggestions that the radiation damage in gold is basically different from that of copper and silver. It is thought that the interstitial in gold differs from that in copper and silver. In connection with the amount of low-temperature annealing, it is thought that focusing and interstitial clustering are important. Deviations from Matthiessen's rule for gold and cadmium are in qualitative agreement with theory. Only qualitative agreement with an earlier experiment on the annealing of cadmium can be confirmed.