New High Frequency Dielectric Mode in Fluorinated Antiferroelecteric Liquid Crystals

Abstract

The promising materials for applications are Antiferroelectric Liquid Crystals. Two dielectric modes were detected in AFLCs, as far [1, 2]. Low frequency mode called P _L with the relaxation frequency around 100 Hz as well as high frequency mode called P _H with the relaxation frequency around 100 kHz. The first (P _L ) is related to in-phase motions of molecules on the cone surface (when two neighbouring layers are taken into account) while the second (P _H ) is related to anti-phase motions of molecules on the cone surface. In recently synthesized fluorinated liquid crystals we detected new high frequency dielectric mode. We called it X-mode. Relaxation frequency is around 1–100 MHz and changes with the temperature.

Keywords:

• antiferroelectric liquid crystals
• dielectric properties
• relaxation frequency

Acknowledgments

This work was sponsored by Polish – Singapore Cooperation 13/2006 entitled “New Orthoconic Antiferroelectric Liquid Crystals for Advanced Display Applications”