A liquid state least-squares procedure for obtaining solid state multicomponent diffusion coefficients from diffusion couples

A procedure is developed for analyzing combined concentration profiles from multicomponent solid-state diffusion data obtained with free-diffusion bou ndary conditions. This procedure is exactly analogous to the analysis of li quid-state diffusion data obtained from free-diffusion refractive-index pro files (e.g. from Rayleigh interferometry). All data from all couples are le ast-squared together to characterize the diffusion coefficient matrix. Diff erent profile weightings provide interesting alternatives, as well as diagn ostics. Symmetric averagings are shown to eliminate or reduce effects of co ncentration dependence. (C) 1998 Acta Metallurgica Inc. Published by Elsevi er Science Ltd. All rights reserved.