Liquid-state diffusion of Na2O–CaO–SiO2 system

Abstract

The concentration distributions after liquid-state diffusion at 1200°C were measured by using an electron probe microanalyzer for two diffusion couples with an average composition of 16Na2O⋅12CaO⋅72SiO2 (wt%). The diffusion profiles agreed satisfactorily with the theoretical profiles calculated by the five-component diffusion equations derived from the Nernst–Planck equation with assumptions of two oxygen ionic species with differing diffusivities and the oxygen density conservation.