DIFFUSION PROCESSES IN THE AU(111)-AG(111) THIN-FILM SYSTEM

The diffusion mechanisms of silver through Au(111) films 360 Å thick for different temperatures and heating times are studied. By means of quantitative Auger electron spectroscopy and in-depth profiling techniques the composition of the first monolayer and the composition profiles of diffused silver against time and heating temperature are determined. After elimination of instrumental effects the bulk silver interdiffusion coefficients for different temperatures and the activation energy of diffusion are obtained. The extrapolation stages allows the time required for the diffused onto the surface in the first diffusion stages allows the time required for the first appearance to be determined. Comparison with two standard expressions gives the corresponding grain-boundary diffusion coefficients and the activation energy. A numerical formalism, which includes the variation of composition at the interface but makes no allowance for grain boundary-grain diffusion, is tested esing the calculated coefficients. The agreement between the experimental results and the theoretical surface compositions is satisfactory within the limitations of the proposed model. © 1979.