Behaviour of the diffusion vacancy-wind factors in the concentrated randomalloy

In this paper, the vacancy-wind factors which appear in the well known expr ession relating the interdiffusion coefficient and intrinsic diffusion coef ficients to the tracer diffusion coefficients are examined in the context o f the random alloy model. it is shown by Monte Carlo simulation that the fo rmalism of Moleko et al. provides a much better description of these factor s than the well known and commonlyused formalism of Manning. Even when the ratio of the tracer diffusion coefficients is relatively close to unity, it is preferable to use the Moleko et al. formalism. The latter formalism is re-expressed in this paper to be suitable for direct experimental use in de terming vacancy-wind factors. The limiting behaviour of the ratios of the t racer diffusivities and intrinsic diffusivities is also discussed. In the l atter case the ratio is given simply (and generally) by the ratio of the ex change frequencies.