Atomic diffusion in liquid Ni, NiP, PdNiP, and PdNiCuP alloys

Abstract

We investigated the self-diffusion of Ni in liquid Ni, Ni80P20, Pd40Ni40P20, and Pd43Ni10Cu27P20 at temperatures up to 1795K with incoherent, quasielastic neutron scattering. Values of measured self-diffusion coefficients vary over the accessible temperature ranges as a function of composition only within 10%. Although mixing has a drastic effect on the liquidus temperature and the undercooling capabilities, a relation between these properties and the atomic diffusion in the liquid is not observed. Apparently, diffusive motion is governed by the packing fraction of the atoms, that is very similar in these dense liquids.