"The diffusivities of Fe, Co, and Al in otherwise pure Au were determined by a residual activity technique. It was found that the frequency factors and activation energies of the transition elements into Au are normal relative to the values for Au self-diffusion, and suggest that lattice diffusion is operative, in contrast to the corresponding situation for the diffusion of these elements in Al. This difference in behavior is explained in terms of the marked difference in solid solubilities in the two series."

The self-diffusivities of Co60 and Ni63 in cobalt--nickel solid solutions exhibit a greater activation energy below the Curie temperature (T/sub c/) than above. Values of DELTA Q = Q (ferromagnetic) -- Q (paramagnetic) are approximately equal to RT/sub c/. This observation is interpreted to indicate that the increment in activation energy arises from an increase in the formation energy of a vacancy in the ferromagnetic lattice, with the additional binding energy arising from the interaction of a spin with the Weiss field."