Impurity diffusion in single crystals was studied, at 777 to 1513K, using secondary ion mass spectrometry. The diffusion coefficients ranged from 4.1 x 10-17 to 2.4 x 10-9cm2/s, and the results could be described by:

D (cm2/s) = 1.1 x 100 exp[-59.5(kcal/mol)/RT]

Short-circuit diffusion occurred at low temperatures.

W.Gust, M.B.Hintz, A.Lodding, H.Odelius: Philosophical Magazine A, 1981, 43[5], 1205-19