Measurements were made of the release of 41Ar and 39Ar from fast neutron-irradiated single crystals. The results for 425 to 625K could be described by:

D (cm2/s) = 7 x 108 exp[-1.80(eV)/kT]

The results for 625 to 1015K could be described by:

D (cm2/s) = 2 x 10-3 exp[-0.36(eV)/kT]

F.W.Felix: Proceedings of the British Ceramic Society, 1967, 9, 273-7

The best linear fits to the solute diffusion data ([336] to [347]) yield:

Ar: Ln[Do] = 0.77E – 13 (R2 = 0.98); Br: Ln[Do] = 0.49E – 18.3 (R2 = 0.88);

He: Ln[Do] = 1.17E – 15.9 (R2 = 0.58)