Goldstone and soft modes for fluorescent dye doped ferroelectric liquid crystal

Abstract The present paper reports the dielectric and electro-optical behavior of pure and fluorescent dye doped ferroelectric liquid crystal (FLC) system. The different parameters such as relaxation frequency, relaxation strength and dielectric permittivity have been determined by dielectric relaxation study. The dielectric relaxation study indicates existence of Goldstone mode for 1% and 2% concentration of fluorescent dye doped mixtures. In addition to this it also shows high frequency mode i.e. soft mode for higher concentration of fluorescent dye i.e. for 2% concentration of fluorescent dye in pure FLC. The other important parameters i.e. spontaneous polarization, response time and rotational viscosity have also been evaluated by electro-optical study. The soft mode observed for high concentration fluorescent dye doped system has been explained and its nature and magnitude are found to be in agreement as reported for other FLCs. It has also been found that all the parameters have been strongly changed by the variation of concentration of the fluorescent dye into pure FLC.