Ordering behavior and electric response of a ferroelectric nano-doped liquid crystal with ion impurity effects

Abstract

We present a theoretical study of the simultaneous effects of ferroelectric nanoparticles and ion impurities on the order parameter of liquid crystals. We have focused on the effect of ion impurities on the ordering behavior and electrical response of a ferroelectric nano-doped liquid crystal near the nematic-isotropic phase transition. In this study, a statistical theory based on the orientational distribution of the nanoparticle dopants is used. We have performed the calculations using the Poisson–Boltzmann equation and a modified Landau-De Gennes model. The total density of free energy of the system is obtained within the framework of this theory, and the changes in the concentration of mobile ions due to the presence of ferroelectric nanoparticles are investigated. It is shown that the screening effect of the ion impurities plays a dominant role in the ordering behavior and electrical response of a ferroelectric nano-doped liquid crystal. The ion generation and the consequent changes are also described in some physical properties of a nano-doped system under an applied electric field.

Eliminating Ambiguities in Electrical Measurements of Advanced Liquid Crystal Materials

“…From both academic and industrial points of view, it is crucial to study electrical properties of such materials. Research results obtained by independent teams during the last two decades point to very non-trivial ionic effects in liquid crystals doped with nanoparticles of different origins (ferroelectric [62][63][64][65][66][67][68][69][70], magnetic [52,[71][72][73][74][75][76][77][78], semiconductor and dielectric [79][80][81][82][83][84][85][86][87], carbon-based [88][89][90][91][92][93][94][95][96][97][98], and metal [99][100][101][102][103][104][105][106], additional references can be found in recent topical reviews [31,…”