The segregation of C to the (100) surface of a (100) crystal slice was studied at 1600 to 2073K. The total amount of C in the crystal was maintained equivalent to 0.8 monolayers on each face. It was deduced that bulk diffusion was described by:

D (cm2/s) = 3 x 100 exp[-59(kcal/mol)/RT]

K.J.Rawlings, S.D.Foulias, B.J.Hopkins: Surface Science, 1981, 109[3], 513-21