Diffusion of cations in sodium-potassium and sodium-barium silicate melts

Diffusion coefficients of sodium and potassium ions in molten glasses with the composition (25 - x)Na2O center dot xK(2)O center dot 75SiO(2) have been determined by the sectioning method with measurement of the residual activity Na-22 and K-42 isotopes. Diffusion of sodium and Ba-133 ions has been studied in melts of the (30 - x)Na2O center dot xBaO center dot 5Ga(2)O(3) center dot 65SiO(2) system. It has been found that the concentration dependences of diffusion characteristics in melts containing alkali and alkaline-earth cations principally differ from the regularities diffusion in dialkali melts.