Diffusion-reaction: Growth and nucleation

The problem to be considered is simple: Why, in metal to metal reactions, should the rules of multiple phase formation based purely on kinetic considerations (diffusion) be usually correct although they ignore initial stages of phase formation that are often well defined in experimental observations? In the paper, the laws of growth are rapidly reviewed. It is then shown that nucleation phenomena can be dominated by kinetic considerations, so that whether one looks at phase formation in diffusion-reactions from the points of view of nucleation or growth, one should often arrive at the same conclusions regarding the order of phase formation. The "ordered Cu3Au rule" is shown to provide a useful link between nucleation and growth.