Phase Sequence in Smectic Liquid Crystals Having Fluorophenyl Group in the Core

Abstract
The phase sequence of a new family of chiral smectic liquid crystals, represented by 4-(1-methylhepthyloxycarbonyl) 3-fluorophenyl 4-dodecylbiphenyl-4-carboxylate (MHFPDBC), were investigated by measurements of dielectric dispersion under various bias field strengths. Three phases, ferrielectric smectic Cγ * phase (SmCγ *), antiferroelectric phase (AF) and ferrielectric phase (FI), were confirmed between ferroelectric SmC* phase and antiferroelectric SmC A * phase. In the dielectric measurements around the ferrielectric phases, an opposite bias treatment prior to the application of the target bias field strength is important. Observed dielectric relaxation modes were discussed together with the results of electrooptical and conoscopic observations.