In-situ TEM study of diffusion kinetics and electron irradiation effects on the Cr phase separation of a nanocrystalline Cu-4 at.% Cr thin film alloy

The Cr phase separation process and kinetics of a metastable Cu(96)C(r)4 alloy film were investigated by isothermal annealing at different temperatures of up to 500 degrees C using transmission electron microscopy. It is shown that the Cr phase separation proceeds predominantly via enrichment of Cr at grain boundaries and grain boundary diffusion. Temperature dependent diffusion coefficients and the activation energy for grain boundary diffusion of Cr in faceecentered cubic Cu are determined from analytical in-situ transmission electron microscopy experiments. In addition, the influence of electron beam irradiation on the diffusion kinetics is considered. (C) 2016 Elsevier B.V. All rights reserved.