Electric Field Induced Transformations and Dielectric Properties in Non-Tilted Phases of a Bent-Core Smectic Liquid Crystal

Abstract

We report the structural and relaxation investigations of an achiral bent-core compound in SmAP_A phase. The studied material undergoes transition from one biaxial state to the other via a uniaxial state under electric field. These transformations are explained as successive transition from antiferroelectric to ferroelectric states, where, the intermediate uniaxial state has the molecular secondary directors in the neighbouring smectic layers perpendicular to each other. We also found that near SmAP_R to SmAP_A phase transition the second harmonic electro-optic response, induced polarization, and the dielectric behaviour hint softening behaviour in the material.

Keywords:

• Antiferroelectric order
• bent-core molecules
• dielectric relaxation
• electro-optic effects
• polarization

Acknowledgment

We acknowledge funding by EU FP7-216025 BIND and SFI RFP 06/RFP/ENE039 projects.