The penetration depth of Br2 into crystals was measured at 375 to 600C by using the OH- center as an indicator. A plot of the inverse square of the penetration depth versus the inverse partial pressure of Br led to a linear relationship. The intercept and slope of the plot showed that the diffusivity could be described by:

D (cm2/s) = 1.7 x 10-1 exp[-0.95(eV)/kT]

T.Ikeda: Journal of the Physical Society of Japan, 1976, 41[6], 1968-73

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)