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Theory of liquid diffusion phenomena

1964; University of Toronto Press; Volume: 12; Issue: 5 Linguagem: Inglês

10.1016/0001-6160(64)90018-5

1878-0768

Hugh A. Walls, W. R. Upthegrove,

Theoretical and Computational Physics

Abstract The available theoretical models for liquid diffusion are critically reviewed. A new theoretical model is developed in which the self-diffusion coefficient is correlated to 1. (1) a geometrical parameter which is defined as the ratio of the diffusing particle radius to the interparticle spacing, 2. (2) a configurational parameter dependent only upon the coordination number of the liquid, and 3. (3) an activation energy which is identical to that for viscosity. This new model accurately predicts the self-diffusion behaviour in ten liquid metals for which data are available. It is shown that the geometrical and configurational parameters can be assigned constant values for the class of liquids comprising the liquid metals. Further, it is shown that even with a temperature independent activation energy the new model predicts the curvature observed in data when the logarithm of the diffusion coefficient is plotted against the reciprocal absolute temperature.