Diffusion Limited Growth in Systems with Continuous Symmetry

To study the effect of slow heat conduction during phase separation, we discuss the relaxation properties of an O(N) symmetric model with phase field type dynamics, where a nonconserved order parameter field couples bilinearly to a diffusive field. In the limit N→∞ we obtain an exact solution. The analysis reveals three different types of growth regimes and a very rich dynamical behavior. Finally the connection with the Mullins-Sekerka instability is expounded.