Unusual Layer-Thinning Transition Observed near the Smectic-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>A</mml:mi></mml:math>-Isotropic Transition in Free-Standing Liquid-Crystal Films

Abstract

Calorimetric and optical reflectivity studies on free-standing partially fluorinated liquid-crystal films have revealed novel melting phenomena. The smectic-$A$-isotropic transition occurs through a series of layer-thinning transitions, causing the films to thin in a stepwise manner as the temperature is increased. The temperature dependence of the film thickness has been found to be well fitted by a simple power law. These results are discussed in the context of present theory and the effects of fluorination are addressed.