The reason for the very high diffusivities of the major elements in these D03 intermetallics was considered. It was recalled that recent quasi-elastic neutron scattering and Mössbauer spectroscopic data had revealed that diffusion in stoichiometric samples occurred via nearest-neighbor jumps on the Fe or Ni sub-lattice. Measurements of phonon dispersion were carried out in order to check whether diffusion in these materials was phonon-assisted. The low energetic barriers to migration which were derived from the phonon data permitted a clear conclusion to be drawn as to the reason for rapid diffusion in these compounds.

O.G.Randl, G.Vogl, W.Petry: Physica B, 1996, 219-220, 499-501