Molecular Crystals and Liquid Crystals, Vol.553, 140-146, 2012
Properties of Non-Tilted Bent-Core Orthogonal Smectic Liquid Crystal
We present the properties of different achiral orthogonal polar smectic phases observed in a homologous series of bent-core molecular compounds. The macroscopically uniaxial SmAP(R) phase transforms to biaxial state by the application of higher electric fields and biaxial SmAP(A) phase undergoes biaxial-uniaxial-biaxial texture transformation with increasing electric fields, i.e., initial antiferroelectric structure transforms into ferroelectric state under higher electric fields and it shows three different optically distinguishable states. The SmAP(AR) phase shows an entirely different response compared to other polar smectic phases under study. The dielectric measurements in the SmAP(AR) phase is the evidence of antiferroelectric behavior of uniaxial state. The polarizing microscopy texture observation supports the corresponding biaxiality measurements.
Keywords:Bent-core molecules;orthogonal biaxial polar Smectic;electro-optic effects;dielectric relaxation;polarization