Reaction Diffusion in Binary Solid-Solid, Solid-Liquid and Solid-Gas Systems: Common and Distinctive Features

摘要

The process of reaction diffusion in binary systems, resulting in the occurrence of chemical compound layers (intermetallics, silicides, oxides, salts, etc.) at the interface between initial substances, is analysed from a physicochemical viewpoint to show that (ⅰ) under conditions of diffusion control the number of growing layers is most likely to be one or two irrespective of the number of chemical compounds on the appropriate phase diagram, (ⅱ) major experimentally observed kinetic dependences can be obtained using a single system of differential equations, (ⅲ) in the case of multiple growth, one inert marker is in general insufficient to decide of the main diffusing species in all the layers formed, (ⅳ) different diffusional contributions of the components to the growth process of a chemical compound layer should not necessarily be regarded as a manifestation of the Kirkendall effect.