Induction of a room temperature ferroelectric SmC* phase in binary mixtures with moderate spontaneous polarization and sub-millisecond switching time

Abstract

A ferroelectric SmC* phase is induced at room temperature in binary mixtures of an achiral biphenyl phenyl-pyrimidine compound and a chiral biphenylyl benzoate ester with an oligomethylene spacer based compound. The lowest temperature (24 °C) and wide range (100°) ferroelectric phase is observed at 10 wt% concentration of the chiral dopant. Optical polarizing microscopy, synchrotron X-ray diffraction, dielectric spectroscopy and electro-optic studies reveal that the mixtures possess various suitable properties including moderate spontaneous polarization and sub-millisecond switching time.