Nematic and smectic phases with proper ferroelectric order

TL;DR

This study reports the synthesis and analysis of a new ferroelectric liquid crystal material exhibiting a sequence of ferroelectric phases, with detailed characterization of their polarization and dielectric properties.

Contribution

It introduces a new material with multiple ferroelectric liquid crystalline phases and provides experimental evidence of their ferroelectric behavior and dielectric responses.

Findings

Ferroelectric phases confirmed by second harmonic generation and polarization switching.

Polarization orientation can be controlled by tilt angle adjustments.

Distinct dielectric responses observed in different smectic phases.

Abstract

A material showing a sequence of three ferroelectric liquid crystalline phases below the paraelectric nematic phase has been synthesized and studied. The polar order of molecules appearing due to the dipole-dipole interactions in the NF phase is preserved also in the smectic phases: orthogonal SmAF and tilted SmCF. The ferroelectric ground state of both smectic phases is confirmed by their second harmonic generation activity and polarization switching. In the SmCF phase the polarization becomes oriented to the electric field by decreasing the tilt angle to zero. Although both smectic phases are ferroelectric in nature, their dielectric response is found to be very different.