Dynamical Properties of Ferroelectric Chiral Liquid Crystals by Electro-Optical and Dielectric Spectroscopy

ABSTRACT

Structural, electro-optical, and dielectric investigations of a ferroelectric liquid crystal (FLC) exhibiting the chiral smectic C phase (SmC∗) are reported. This study has been performed on the pure FLC showing the SmC∗–SmA–N∗ phase sequence and having high spontaneous polarization and a large relaxation frequency. We have determined the Goldstone rotational viscosity and the twist elastic constant in the SmC∗ phase from the experimental data of helical pitch, tilt angle, polarization, dielectric strength, and relaxation frequency of the Goldstone-mode relaxation. An Arrhenius-type behavior of the Goldstone rotational viscosity was obtained, and the corresponding activation energies were evaluated.

KEYWORDS:

• dielectric relaxation spectroscopy
• electro-optical study
• ferroelectric liquid crystals
• Goldstone mode
• rotational viscosity
• twist elastic constant

Notes

Cr, crystalline phase; Sm, smectic phases A, C∗; N∗, cholesteric phase; BP, blue phase; I, isotropic phase; ( ), monotropic transition.