Effect of enantiomeric excess on the smectic-C* phases under electric field

A series of enantiomeric mixtures of 4-(1-methylheptyloxycarbonyl) phenol 4'-octyloxybiphenyl-4-carbonate (MHPOBC) is reported to understand the structures and stability conditions of emerging liquid crystal phases. The mesomorphic properties are studied by microscopic observation, electro-optic and dielectric measurements. The electric field-concentration (E-x) phase diagram for each phase at constant temperature is constructed. The complete electric field-temperature (E T) phase diagrams for several enantiomeric mixtures of the antiferroelectric MHPOBC are established. These phase diagrams show the influence of optical purity on the phase stability and the unwinding threshold.