SIMULATION STUDY OF NUCLEATION IN A PHASE-FIELD MODEL WITH NONLOCAL INTERACTIONS

We examine the phenomenon of nucleation in a two-dimensional phase-fie ld model in order to calculate quantities associated with a field-theo retic model and to determine the impact of spatially nonlocal interact ions on both droplet morphology and nucleation rate. We use an approxi mate numerical technique, together with model A Langevin dynamics, in order to characterize the saddle surface that separates stable and met astable states in function space. We thus obtain the free energy of fo rmation of a critical droplet as well as the statistical prefactor, wh ich, except for a dynamical prefactor, determine the nucleation rate. The standard Ginzburg-Landau energy is employed and, in addition, we c onsider the role of a short-range, spatially nonlocal interaction on n ucleation.