Radiation-enhanced diffusion in metals. Ordering in annealed silver-zinc alloys

By the method of resistivity measurement at −197 °C, ordering in the annealed Ag+ +8.75 at% Zn alloy samples has been investigated under electron irradiation of 2.3 MeV, at temperatures from −20 to +190 °C and electron fluxes from 9.35 × 1012 to 4.66 × 1013 cm−2 s−1. The resistivity change during the ordering has been found to obey the second order kinetics. The temperature dependence of the radiation-enhanced diffusion coefficient is described by an exponential with an activation energy of 0.41 eV. The diffusion coefficient varies as the square root of electron fluxes. Analysis of the results obtained led to a conclusion that in a well-annealed metal (small concentration of dislocations) the radiation-enhanced diffusion is steady. Annihilation of interstitials and vacancies is the diffusion controlling process, the motion of interstitials in the dumbbell configuration being responsible for contribution to the diffusion flow.