The activation energy for solute diffusion in the ferromagnetic state of Fe could be represented by Qp(1+as2), where Qp was the activation energy in the paramagnetic state, s was the ratio of the spontaneous magnetization at T to that at 0K. The constant, a, for self-diffusion and diffusion of Co, Cr, Mo, Nb and Ti in a-Fe was determined experimentally. Upon compiling these values of a, it was found that the constant a could be expressed as a linear function of ΔM, which was the change of magnetization of Fe on dilution with solute elements, if ΔM was taken for the first and second shells of the solute atom.

Influence of Magnetization Change on Solute Diffusion in Iron. H.Nitta, Y.Iijima: Philosophical Magazine Letters, 2005, 85[10], 543-8