Calorimetric and optical microscopic studies on one ferroelectric liquid-crystal compound with the smectic-A/emph>phase

Detailed calorimetric measurements have been carried out on the chiral and racemic versions of one chiral liquid-crystal compound that exhibits an unusual and new smectic-$A^{\mathrm{*}}$ (Sm-$A^{\mathrm{*}}$) phase in the pure chiral compound. Both the smectic-A (Sm-A)–smectic-C (Sm-C) transition in the racemic compound and the Sm-$A^{\mathrm{*}}$–chiral–Sm-C transition in the pure chiral compound display a first-order transition with heat-capacity anomalies qualitatively similar to but quantitatively different from that observed in the ordinary Sm-A–Sm-C transition. Results from optical microscopic studies on the phase diagram of binary mixtures of the dextro and levo versions of the chiral compounds are reported.