LATE-STAGE KINETICS OF SYSTEMS WITH COMPETING INTERACTIONS QUENCHED INTO THE HEXAGONAL PHASE

We study the late-stage kinetics for systems with long-range repulsive and short-range attractive interactions, quenched into the hexagonal phase. The system displays two qualitatively different regimes: a mono disperse hexagonal regime and a polydisperse coarsening regime. In the first regime, the evolution of the system towards the hexagonal order characteristic of the crystal ground state is studied. The mechanisms of defect collision and annihilation are identified, and the temporal evolution of orientational and translational order is described. In t he coarsening regime, the results of the simulations closely resemble those obtained for a two-dimensional binary mixture confined to an air -water interface. In this regime the system can be described as a two- dimensional froth, with a strong coupling between its topological and geometrical quantities.