Calculation of the Dielectric Constant as a Function of Temperature Near the Smectic AC* Phase Transition in Ferroelectric Liquid Crystals

Abstract

We calculate here the dielectric constant ϵ as a function of temperature for the AC* phase transition of a ferroelectric liquid crystal using a mean field model. Using the values of the polarization P and the tilt angle θ, calculated from the mean field model with the P²θ² coupling for 4-(3-methyl-2-chlorobutanoyloxy)-4′-heptyloxybiphenyl, the dielectric constant ϵ is calculated in the smectic C* phase of this ferroelectric liquid crystal at various temperatures at constant electric fields.

Our calculated ϵ values predict the critical behaviour of the experimental dielectric constant measured at 15, 30, 45 and 60 V for 4-(3-methyl-2-chlorobutanoyloxy)-4′-heptyloxy-biphenyl, as reported in the literature.

Keywords:

• dielectric constant
• AC* phase transition