Smectic-<i>A–</i>hexatic-<i>B</i>transition of various compounds in the homologous series of<i>n</i>-alkyl-4’-n-alkoxybiphenyl-4-carboxylate

Abstract

Extensive high-resolution heat-capacity measurements have been carried out near the smectic-A--hexatic-B transition of various compounds in the homologous series of n-alkyl-4'-n-alkoxybiphenyl-4-carboxylate. In contrast with the nematic--smectic-A and smectic-A--smectic-C (or chiral-smectic-C) transitions, the critical exponent \ensuremath{\alpha} characterizing the smectic-A--hexatic-B heat-capacity anomaly is found to be large and does not vary monotonically with the size of the disordered-phase (i.e., smectic-A) temperature range.