The diffusion of 22Na in 6N-purity material was studied at 249 to 313C. The results could be described by:

D (cm2/s) = 6.3 x 100 exp[-28.3(kcal/mol)/RT]

C.W.Owens, D.Turnbull: Journal of Applied Physics, 1972, 43[10], 3933-6