Treatment of Diffusionprofiles with the Method of Nets

Abstract

Abstract Diffusion measurements on the copper-nickel-system were made with two kinds of geometries. Thin Cu-films were evaporated on Ni-single crystals and single crystals of Ni and Cu were brought into contact as semi-infinite solids. Different methods of evaluating the concentration dependent diffusion coefficient were used and the results discussed. Specimens with copper layers of a thickness of up to 10% of the penetration depth can be evaluated with the thin film solution. The accuracy is satisfactory as well with respect to the diffusion coefficient at the nickel boundary as to the layer thickness. Beyond 10% the erf-solution for the thick layer yields good values for the diffusion coefficient but not for the layer thickness. The method of nets, using the difference equation, is a powerful tool to treat nearly any initial condition and any concentration dependence of the diffusion coefficient.