A Commentary on 'Diffusion, Mobility and Their Interrelation through Free Energy in Binary Metallic Systems,' L.S. Darken: Trans. AIME, 1948, vol. 175, p. 184ff

摘要

As an undergraduate and graduate student of metallurgy, the subject of diffusion at first appeared to me as being rather empirical when compared with thermodynamics. It wasn't until the end of the course when multicomponent diffusion was discussed and when Darken's phenomenological equations were described that I appreciated the fundamental nature of diffusion and how the earlier descriptions of flux were really only special cases of Darken's description in his classic article. Indeed, now that I teach diffusion and transport myself, I often wonder whether the subject should be introduced through Darken's equations, which related diffusivity to mobility and activity, rather than through Fick's First Law. In his classic article titled "Diffusion, Mobility and Their Interrelation Through Free Energy in Binary Metallic Systems," Dr. Darken presents his phenomenological analysis of diffusion on binary systems. It is divided into two interrelated sections, with the first handling the issue of marker movement and the second handling the effect of nonideality on diffusion.