Calorimetric investigation of the smectic-C-smectic-I transition in free-standing p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate films

High-resolution heat-capacity data near the smectic-C-smectic-I transition in free-standing p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate (DOBAMBC) films down to only two molecular layers in thickness have been obtained. The data reveal preferential surface ordering phenomena and surface transitions localized to individual smectic layers. Moreover, the data from two-layer films are not consistent with existing theory, and indicate that the present understanding of the liquid-crystal hexatic phases is not complete.