Field-induced phase transition in an antiferroelectric liquid crystal

Field-induced antiferroelectric-ferroelectric phase transition in an antiferroelectric liquid crystal 4-(1-trifluoromethylheptyloxycarbonyl)phenyl-4'-octyloxybiphenyl-4-carboxylate (TFMHPOBC) was studied by means of microscopic observation during the switching process and the measurement of the T-E hysteresis loops. It was clarified that the threshold voltage of the switching from the antiferroelectric state to the ferroelectric state and the transmittance at the threshold voltage depend on temperature, frequency and optical purity. The optical purity is an important factor for improving the contrast of display devices.