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

We observe, in free-standing films of a chiral smectic, liquid crystal, a series of discrete transitions in the relative orientation of the till of the interior and surface layers. These transitions include a remarkable reentrant synclinic-anticlinic-synclinic ordering sequence of the film surfaces in the presence of an electric field upon cooling. The profiles of the associated heat-capacity anomalies are found to be strongly thickness-dependent and exhibit a novel crossover behavior in reduced dimensions.