Ferroelectric Liquid Crystal Mixtures Doped with Compounds Having Chiral Groups at Both Ends of the Core

The transition temperature from chiral smectic C (Sm*C) phase to smectic A (SmA) and the spontaneous polarization (Ps) of mixtures having two components of normal ferroelectric liquid crystal and a compound having two optical active 1-methylheptyl groups at both ends of the core have been investigated. The SmA-Sm*C transition temperature and the magnitude of Ps for the mixtures were found to depend on the absolute spatial configuration of both chiral groups. The maximum Ps (225 nC/cm2) was observed in a mixture doped with a compound whose chiral groups were classified into the same polarity as that of the host ferroelectric liquid crystal.