Thermal Property Evolution Toward Effectively Two-Dimensional Substrate-Free Systems

ABSTRACTA high-resolution differential quasi-adiabatic calorimeter has been developed to investigate the physical properties of freestanding liquid-crystal films. Our recent heat-capacity studies near the smectic-A-hexatic-B transition of both 65OBC and 46OBC freestanding films clearly demonstrate the evolution towards twodimensional limiting behavior in four-layer films. As the film thickness decreases towards four molecular layers, the heatcapacity anomalies first display separate peaks for the surface and interior transitions and then evolve to one dominated by the surface transition.