Unusual thickness-dependent thermal behavior and anticlinic coupling in chiral smectic free-standing liquid-crystal films

We observe, in free-standing films of a chiral smectic liquid crystal, a se ries of discrete transitions in the relative orientation of the tilt of the interior and surface layers. These transitions include a remarkable reentr ant synclinic-anticlinic-synclinic ordering sequence of the film surfaces i n the presence of an electric field upon cooling. The profiles of the assoc iated heat-capacity anomalies are found to be strongly thickness dependent and exhibit a novel crossover behavior in reduced dimensions. We measure th e anticlinic coupling between tilted surface layers in the smectic-A phase.