DYNAMICS OF UNDULATION INSTABILITY IN LAMELLAR SYSTEMS

We numerically investigate dynamics of undulation instability of lamel lar systems induced by an external field. In particular, if the field is much larger than the critical value, initial undulations are much f iner than those in the final state. The coarsening law here is obtaine d both numerically and theoretically. We also demonstrate that the pat terns are square grids if the field is perpendicular to the lamellae, while they are one-dimensional if it is parallel.