It was recalled that a moving reference frame Monte Carlo method had been used to illustrate graphically how the vacancy-wind effect operated in an ionic solid with a dilute solute and in chemical interdiffusion in concentrated alloys and ionic compounds. The strategy was extended here to show how the effect operated in interdiffusion in a stoichiometric intermetallic having the B2 structure. A simple 4-frequency vacancy diffusion model was used. It had been shown that - depending upon composition and temperature - this model could exhibit the six-jump cycle mechanism. It was shown that, in the limit of perfect order, there was no vacancy-wind effect associated with this mechanism when both types of cycle operated equally (zero net vacancy flux). The non-unity value of the vacancy-wind factor, found for this mechanism under zero vacancy flux conditions, was purely the result of a particular geometric mix of tracer and collective atom displacements. The concept that a non-zero off-diagonal phenomenological coefficient provided the vacancy-wind effect was verified.

The Nature of the Vacancy-Wind Effect Occurring in Diffusion via Six- Jump-Cycles in B2 Intermetallics. I.V.Belova, G.E.Murch: Defect and Diffusion Forum, 2010, 297-301, 1218-25