Silver Grain Boundary Diffusion In Pd

摘要

Two to ten nanometer thick polycrystalline Pd films were prepared on the (1 1 1) surface of Ag single crystal and investigations of the Ag diffusion along Pd grain boundaries were carried out using the Hwang-Balluffi method. The samples were monitored by Auger electron spectroscopy (AES) during isothermal heat treatments in the 438-563 K temperature range. Using plausible simplifying assumptions, the activation energy of the product of the grain boundary (GB) diffusion coefficient and k' (k' = c_s/c_(gb); c_s and c_(gb) are the surface and GB concentration, respectively) was calculated (0.99 ± 0.08 eV) from the evaluated saturation coefficients of the surface accumulation. This energy, for weak temperature dependence of k', is approximately equal to the activation energy of the GB diffusion.