The serial sectioning radiotracer method was used to study the diffusion of 59Fe in single crystals at 533 to 1093C. A chemical sectioning technique was used at lower temperatures. It was found that the activation energy was sharply peaked at the Curie point. The results could be described by:

7.64at%Si:     D (cm2/s) = 1.38 x 100 exp[-54.5(kcal/mol)/RT]

11.1at%Si:     D (cm2/s) = 6.30 x 10-1 exp[-50.7(kcal/mol)/RT]

H.V.M.Mirani, R.Harthoorn, T.J.Zuurendonk, S.J.Helmerhorst, G.de Vries: Physica Status Solidi A, 1975, 29[1], 115-28