Effect of smectic A temperature width on the soft mode in ferroelectric liquid crystals

Abstract

The behavior of soft mode range with respect to the temperature width of smectic A (Sm A) phase has been studied in four different ferroelectric liquid crystal (FLC) materials in the frequency range 10 Hz-10 MHz. The studies have been carried out in a planarly well aligned cells at different temperatures and different bias fields in Sm C* and Sm A phases. Dielectric studies of these FLCs near Sm C* -Sm A phase transition show that the temperature range of soft mode relaxation frequency phenomenon varies with the temperature width of Sm A phase. The dependence of tilt angle on temperature shows the nature of the order of transition at Sm C* -Sm A phase. The coupling between order parameters of Sm C* and Sm A phase influences the soft mode and phase transition in Sm C* and Sm A phases. © 2008 American Institute of Physics.