Inert gas diffusion in silver—I. Cold worked silver

Abstract

The mobility of the heavy rare gases Kr, Xe and Rn was studied in cold-worked silver. The ion bombardment technique with energies between 3 and 85 keV was chosen to introduce the gas into the solid. Gas release measurements were correlated with measurements of diffusion profiles by a chemical sectioning method. Gas mobility was found to be enhanced as compared to pre-annealed recrystallized silver and to be connected to the recovery of the cold-worked state or hence to the recrystallization of the metal. Gas release occurred towards the surface only and was explained as being due to sweeping by annihilating dislocations. Tentatively, an activation enthalpy of 31 ± 1 kcal/mole (or 1.35 ± 0.05 eV) was deduced for this enhanced release, in fair agreement with literature data obtained from the recovery of the electrical resistivity. The present results, together with those reported in a subsequent paper on rare gas mobility in pre-annealed, recrystallized silver, can explain the abnormally big scatter in the previous literature.