Chemically condensed liquid crystalline optical materials dielectric relaxation and phase variance of novel switching applications

Abstract

Dielectric relaxations are studied at three different frequencies of a hydrogen bond liquid crystals composed of chloro benzoic acid with nonyloxy benzoic acid. The process of synthesis is described and the synthesized mesogen is a monophase variant with nematic phase. Hence, FT-IR studies conform the formation of hydrogen bond. Moreover, DSC studies enabled to examine the transition temperatures and corresponding enthalpy values. Profiles of dielectric loss variation with frequency from 5 Hz to 13 MHz are constructed and three different dielectric relaxations labelled as soft mode I relaxation, type II relaxation and type III relaxation at 1 KHz, 6577 KHz and 7654 KHz respectively are observed and investigated. Cole-Cole plots are constructed for all the dielectric relaxations. Arrhenius plots enabled to envisage the activation energies. For the first time in the history of liquid crystal dielectric work, we observed that in the present sample at higher frequency the process mentioned above is reversed. All the dielectric data points obtained at various temperatures when plotted they are found to converge at the ε∞ values and diverge at ε0 values. This process is referred as frequency cross over. Nematic growth order derived from dielectric studies is also presented.