Effect of Electron Irradiation on Diffusion in Gold-Silver Alloys

Abstract

The effect of electron irradiation on diffusion in gold‐silver alloys at ‐196°C was determined from the decrease in amplitude of short wavelength (11–20 Å) composition modulations produced by vapor deposition. It was found that (i) mixing occurred during irradiation. For an electron current of 2 μA cm⁻² at 2 MeV the effective interdiffusivity was approximately 1 × 10⁻²² cm² sec⁻¹. (ii) The interdiffusivity was directly proportional to the electron current and increased with increasing electron energy. (iii) During warm‐up to room temperature after irradiation a single stage of mixing was observed above −70°C. The mixing during irradiation is attributed to the migration of interstitialcies to sinks and that during warm‐up to the migration of vacancies to sinks. These results support the hypothesis that annealing stages around 0°C in pure fcc metals are due to vacancy migration.