The serial sectioning technique was used to investigate the diffusion of 85Sr and the simultaneous diffusion of 85Sr and 57Co into single crystals with a divalent impurity concentration of about 5 x 10-7/cm3. The data for the diffusion of 85Sr2+ alone, at 600 to 750C, could be described by:

D (cm2/s) = 4.13 x 10-2 exp[-1.36(eV)/kT]

The data for the simultaneous diffusion of 57Co2+ and 85Sr2+, at 600 to 750C, could be described by:

D (cm2/s) = 6.4 x 10-6 exp[-0.96(eV)/kT]

in the near-surface region, and by:

D (cm2/s) = 2.8 x 10-3 exp[-1.06(eV)/kT]

in the bulk

A.R.Allnatt, P.Pantelis: Transactions of the Faraday Society, 1968, 64[8], 2100-5

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)