It was found that the data for 14C diffusion at 1450 to 2200C could be described by:

D (cm2/s) = 1.2 x 10-2 exp[-40.3(kcal/mol)/RT]

P.Son, S.Ihara, M.Miyake, T.Sano: Journal of the Japan Institute of Metals, 1966, 30[12], 1137-40