A correlation between surface effect and pitch value of flc material by dielectric method

Abstract

The studies of two ferroelectric liquid crystal materials (FLCs), having different helical pitch values, have been performed in thin (2.5 μm) cell by dielectric methods in the frequency range of 10 Hz to 10 MHz. The results have been recorded on a strongly anchored planarly aligned ferroelectric liquid crystal material which was done by coating one electrode of the cell with polymer and rubbed. The influence of surface effect on the behaviour of the Gold-stone mode has been investigated for positive and negative polarity bias field to the rubbed surface of the cells. It has been observed that in thin cells the dielectric permittivity due to the Goldstone mode in the smectic C* phase is completely different by applying bias field in ferroelectric liquid crystal materials, having different helical pitch value. The results have been discussed in view of how the surface effect influences the phase fluctuation (Goldstone mode) behaviour in smectic C* phase. A correlation between surface effect and helical pitch value of FLC material is drawn and discussed.