We report specific-heat measurements for a series of liquid crystals imbedded in a porous cylindrical geometry. Above the nematic-to-isotropic transition and dependent on nematic width (or chain length), the specific heat shows a small peak. In analogy to known ellipsometry results, the peak is believed to be the signature of a nematic prewetting transition.
X-Ray Studies of the Hexatic Phase in Liquid-Crystals With a Crystal-B-Hexatic-B-Smectic-A Phase Sequence10/15/1994
Free-standing monodomain thick films of three liquid crystalline compounds were examined by x-ray scattering. These compounds exhibit a unique enantiotropic crystal-B-hexatic-B-smectic-A phase sequence with no evidence of herringbone order. The hexatic order parameter Cg changes in the hexatic phase with critical exponent beta=0.15+/-0.03. Temperature dependence of the in-plane positional order correlation length suggests a strongly first-order hexatic-B to crystal-B phase transition with indiscernible enthalpy change.