CHAPTER VIII – Diffusion

Publisher Summary Most of the kinetic phenomena in solids involve diffusion, or a unit step very similar to that operating in diffusion. This chapter provides a study of kinetic phenomena with a study of the fundamentals involved in diffusion in various materials. Further illustrates a phenomenological treatment of linear processes that is based on the thermodynamic theory of irreversible processes. This general approach is made specific by application to diffusion in a binary alloy. Diffusion in ionic crystals and semiconductors essentially follows on the basis of the relations developed for metals and the thermodynamics of defects in these materials. The chapter discusses diffusion along high diffusivity regions, such as grain boundaries. Description of computer assisted strategies for extending the basic concepts to problems involving multicomponent diffusion in technological applications is reviewed. Diffusion of polymer strands is also presented briefly.