SIZE RELATION FOR SURFACE SYSTEMS WITH LONG-RANGE INTERACTIONS

From the minimization of the free energy it follows that strained laye rs and, more generally, surface systems governed by effective long-ran ge interactions decaying as 1/r2 will exhibit periodically ordered dom ain structures. We show that there exists a firm relation between the size of a single domain (at low domain concentrations) and the minimum separation between them at intermediate concentrations. This size rat io is about 1:3. It is independent of the symmetry (striped or various two-dimensional arrangements) of the domain pattern. This size relati on is indeed observed for a variety of different systems.