Layer-by-layer surface ordering near a continuous transition in free-standing liquid-crystal films

High-resolution heat-capacity experiments on free-standing films of the liquid-crystal compound 3(10)OBC near the smectic-A--hexatic-B phase transition have been conducted. The hexatic-B phase has been found to propagate into the smectic-A phase through a series of layer transitions, each appearing to be continuous. Furthermore, the evolution of the layer-by-layer transitions is shown to be inconsistent with recent theory regarding the fluctuation-induced forces of the highly anisotropic smectic phases.