Spark-source mass spectrometry methods were used to study the diffusion of Fe at 965 to 1625C. The results could be described by:

D (cm2/s) = 5 x 10-3 exp[-19.3(kcal/mol)/RT]

for α-Th and by:

D (cm2/s) = 4 x 10-3 exp[-17.1(kcal/mol)/RT]

for β-Th.

W.N.Weins, O.N.Carlson: Journal of the Less-Common Metals, 1979, 66[1], 99-110