The serial sectioning technique was used to study the diffusion of 22Na+ in single crystals. The data, for 450 to 750C, could be described by:

D (cm2/s) = 3.32 x 101 exp[-1.98(eV)/kT]

in the intrinsic range, and by:

D (cm2/s) = 1.59 x 10-3 exp[-1.24(eV)/kT]

in the extrinsic range.

The results showed that the diffusion of the ions involved 2 mechanisms; one of which characterized the intrinsic regime and the other the extrinsic regime.

F.Bénière, M.Bénière, M.Chemla: Journal de Chimie Physique et de Physicochimie Biologique, 1969, 66[5], 898-902

The best linear fits to the solute diffusion data ([382] to [383], [391] to [397], [403] to [405]) yield:

Cs: Ln[Do] = 0.29E – 9.9 (R2 = 0.73); Na: Ln[Do] = 0.57E – 22.4 (R2 = 0.99);

Sr: Ln[Do] = 0.55E – 20.5 (R2 = 0.51)