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

D (cm2/s) = 2.0 x 10-1 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.

A.P.Batra, L.M.Slifkin: Journal of the Physics and Chemistry of Solids, 1976, 37[10], 967-9

The best linear fit to the solute diffusion data ([348] to [365]) yields:

Mn: Ln[Do] = 0.87E – 22.7 (R2 = 0.99)