A wide range room temperature antiferroelectric liquid crystal mixture with moderate spontaneous polarization and sub-millisecond switching time

Abstract

A room-temperature antiferroelectric liquid crystal (AFLC) mixture has been prepared by doping two chiral fluorinated compounds into a four-component achiral phenyl pyrimidine-based host matrix. The suitability of the mixture for practical applications has been tested by optical polarizing microscopy, synchrotron X-ray diffraction, frequency-dependent dielectric, and electro-optic studies. The mixture possesses an antiferroelectric phase over a wide temperature range (nearly 82 °C) followed by a paraelectric phase for 13.7 °C. It is found to display very fast switching between 243 and 45 μs at the driving voltage of 3.2 V/μm in the SmC*A phase. At 20 °C, the mixture exhibits a moderately high spontaneous polarization (137 nC/cm2), low viscosity (1.01 Pa s) and fast switching (240μs). The formulated mixture is thus expected to be suitable for use in fast-response AFLC-based display devices.