Concentration-dependent diffusion coefficients for 85Sr2+ in ion-exchanged NaCl were determined by using a sectioning method. Isothermal diffusion annealing was performed at 448 to 683C. The saturation diffusion coefficients, enthalpies and entropies of impurity-vacancy associations were calculated by using the common-ion model for the simultaneous diffusion of divalent ions in alkali halides. The saturation diffusion data could be described by:

D (cm2/s) = 2.30 x 10-3 exp[-0.93(eV)/kT]

H.Machida, W.J.Fredericks: Journal de Physique - Colloques, 1976, 7, 385-91

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)