It was known that a reduction in the number of independent interdiffusivities and intrinsic diffusivities was possible if thermodynamic ideality of the (ternary) alloy was assumed or if the off-diagonal phenomenological coefficients were ignored. A new analysis was presented here which showed generally, and exactly, that a reduction in the number of independent interdiffusivities and intrinsic diffusivities was always possible for ternary and higher alloys. In the general case, thermodynamic activities were also required.

Relations between Interdiffusivities and Intrinsic Diffusivities in Ternary and Quaternary Alloys. I.V.Belova, G.E.Murch: Philosophical Magazine Letters, 2003, 83[1], 73-7