KINETICS OF QUENCHED SYSTEMS WITH LONG-RANGE REPULSIVE INTERACTIONS

The kinetics of a quenched system with a nonconserved order parameter having both an attractive and a long-range repulsive interaction (specifically a uniaxial ferromagnetic film) is studied. The presence of the repulsive interaction leads to the formation of periodically modulated structures. For various physical situations, the kinetics is studied through numerical integration of the appropriate Langevin equation. As the strength of the repulsive interaction is increased, we find that at intermediate times the effective domain-growth exponent decreases continuously from one-half to zero. For the case of a system in zero external field and at zero temperature, we have constructed a dynamical theory based on a singular perturbation expansion. The theory compares well with the results of numerical simulation. It accounts for the formation of modulated domain structures with sharp interfaces and the saturation of the order parameter but not the late-stage phenomena. © 1990 The American Physical Society.