EFFECTS OF LONG-RANGED INTERACTIONS ON THE NUCLEATION DYNAMICS IN A PHI(6) MODEL

It is known that long-ranged interactions can play an important role i n determining the dynamics of nudeation at a first-order phase transit ion. For example, in a recent Letter by the present authors [Phys. Rev . Lett. 74, 3848 (1995)] it was shown that during the annealing of an amorphous thin film, long-ranged interactions generated by strains due to elastic misfits could be responsible for the system becoming trapp ed in a metastable secondary crystalline phase. In this paper we consi der these long-ranged interactions in a more general context wherein o nly symmetry considerations are invoked to determine if a particular i nteraction potential is allowed. Their effects on a first-order phase transition, as described by a single-component scalar phi(6) model, ar e examined. These transitions are studied by means of Langevin simulat ions. We find, through the evaluation of the time evolution of the ord er parameter, the morphology of the steady state, and the time-depende nt structure factor, that the precise form of the long-ranged interact ion has a strong influence on the nature of nucleation dynamics, as we ll as on the steady-state profiles.