Nonlinear Dielectric Spectroscopy on Antiferroelectric Liquid Crystal MHPOCBC-I : Amplitude Mode in SmC_α^* Phase

Abstract

We have performed the nonlinear dielectric measurements in an antiferroelectric liquid crystal MHPOCBC and observed the amplitude mode in the high temperature region of SmC_α^* phase. A Landau-type theory was developed in order to analyze the experimentally obtained frequency dispersions in the third-order nonlinear dielectric response and it was found that the SmA-SmC^*_α phase transition is close to a tricritical point.