Nucleation and coarsening in binary condensed phases

Abstract

The evolution of a thermodynamically unstable binary mixture was simulated by a digital computer. Isothermal formation and growth of two-dimensional nuclei by means of molecular diffusion only was studied. The system is thought to model an alloy, a very viscous liquid, or possibly a surface film. Evaluation of average nuclear size and the spatial correlation function suggest the existence of three regimes. In the first the nuclei are formed and most of the fine scale inhomogeneity decays, During the second period enrichment of the new phase occurs by way of active Fickean diffusion with little change in morphology. The final stage consists of nonlinear processes during which droplets join to form larger aggregates.