Diffusion through membranes was studied at up to 600C. The results were found to be described by:

D (cm2/s) = 1.8 x 10-1 exp[-14.8(kcal/mol)/RT]

M.Braun, B.Emmoth, F.Waelbroeck, P.Wienhold: Journal of Nuclear Materials, 1980, 93-94, 861-5