A modified electrostatic model for the diffusion of electropositive impurities in noble metals I. Impurity diffusion and isotope effect

A modified electrostatic model for the diffusion of electropositive impurities in noble metals, is developed by combining assumptions made in the original electrostatic model (Le Claire 1962) and in the thermodynamic model (Neumann and Hirschwald 1973, 1974) of impurity diffusion. The calculations are based on the five-frequency model, taking into account of divacancy contribution at higher temperature. The calculated diffusion coefficients and isotope effects are compared with experimental data.