The diffusion of Cs+ tracers was measured, at temperatures ranging from 327 to 447C, by using standard serial sectioning techniques. It was found that the data (table 34) could be described by:

D (cm2/s) = 0.20 exp[-0.83(eV)/kT]

The unexpectedly low activation energy, and tracer diffusivities that were higher than those of substitutional Ag+, were attributed to local strains, in the lattice, that were caused by the large ionic radius of Cs; with the concomitant strong binding of a cation vacancy.

Fast Diffusion of Cs+, a Large Alkali Ion, in Silver Chloride. A.P.Batra, L.M.Slifkin: Journal of Physics and Chemistry of Solids, 1976, 37[10], 967-9

Table 34

Diffusivity of Cs+ in AgCl Single Crystals