Dielectric behaviour of a ferroelectric liquid crystal dimer

Abstract

The present work deals with the dielectric behaviour of a ferroelectric liquid crystal (FLC) dimer. Small values of relative permittivity and dielectric loss for the FLC dimer have been observed. The soft mode at high frequency has been observed near the smectic A-chiral smectic C (SmA−SmC*) transition temperature with a very small value of relaxation strength, which becomes insignificant at higher temperatures in the SmA phase due to intramolecular reorientation. The goldstone mode has not been detected for the complete SmC* phase of the FLC dimer because of the small value of spontaneous polarisation at low applied electric field. The observed dielectric response is attributed to the bulky cholesteryl ester segment. The low value of the relative permittivity and dielectric loss suggests that it may be applicable in spatial light modulators and signal processing if it gives the high electro-optical response at low electric field with suitable doping.