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

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 polarising microscopy, synchrotron X-ray diffraction, frequency-dependent dielectric, and electro-optic studies. The mixture possesses an antiferroelectric phase over a wide temperature range (nearly 82oC) followed by a paraelectric phase for 13.7oC. It is found to display very fast switching between 243-45µs at the driving voltage of 3.2V/µm in the SmC*$_A$ phase. At 20°C, the mixture exhibits a moderately high spontaneous polarization (137nC/cm$^2$), 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.