Simulations of metastable decay in two- and three-dimensional models with microscopic dynamics

We present a brief analysis of the crossover phase diagram for the decay of a metastable phase in a simple dynamic lattice-gas model of a two-phase sy stem. We illustrate the nucleation-theoretical analysis with dynamic Monte Carlo (MC) simulations of a kinetic Ising lattice gas on square and cubic l attices. We predict several regimes in which the metastable lifetime has di fferent functional forms, and we provide estimates for the crossovers betwe en the different regimes. In the multidroplet regime, the Kolmogorov-Johnso n-Mehl-Avrami (KJMA) theory for the time dependence of the order-parameter decay and the two-point density correlation function allows extraction of b oth the order parameter in the metastable phase and the interfacial velocit y from the simulation data. (C) 2000 Elsevier Science B.V. All rights reser ved.