FIELD-INDUCED SMECTIC-A TO SMECTIC-C TRANSITION IN FERROELECTRIC LIQUID-CRYSTALS WITH A CHIRAL GROUP ON EACH END OF THE CORE

The smectic A to chiral smectic C transition was studied in dichiral ferroelectric liquid crystals with an optically active alkanoyl group on one end of the core and another chiral group on the other end. Two electric current peaks were observed when a triangular-wave electric field was applied to the dichiral compounds in the smectic A phase. Texture observation and induced tilt angle measurement under an electric field revealed that these two current peaks ale attributable to an electric-field-induced smectic A to smectic C phase transition. Differential scanning calorimetry and spontaneous polarization measurement showed that the smectic A to chiral smectic C transition of the dichiral compounds is first-order. The field-induced transition is attributed to the large spontaneous polarization and the first-order property of the transition.