The self-diffusion of Na+ and Cs+, in hydrated material which had been heated at 50, 200 or 400C, was determined as a function of the ion exchange capacity. It was found that the mobility of these ions decreased with increasing heating temperature and ion exchange capacity. For a given capacity, the diffusivity of Na+ was higher than that of Cs+ for every heating temperature.

I.M.El-Naggar, M.I.El-Dessouky, H.F.Aly: Solid State Ionics, 1992, 57[3-4], 339-43