ABSTRACT
Once the size of the critical nucleus exceeds that corresponding to n*þ d=2, at DG8¼DG* kT (see Figures 2.1 and 2.9), the probability that a chance thermal fluctuation will cause the loss of an atom that will initiate dissolution of the nucleus becomes sufficiently small so that the diffusional growth stage can be considered to have been entered. When growth has proceeded a little further, to the point where DG8< 0, the dominating influence that interfacial energy minimization exerts upon precipitate shape during the nucleation stage can be considered to have been largely overthrown. The characteristics of further growth should now rapidly approach those of the ‘‘macroscopic,’’ that is, supra-micron size regime.
