Resolving the isolated nature of Goldstone mode in ferroelectric liquid crystals at room temperature

Abstract

Herein, we have investigated the effect of surface contributions on the dielectric properties of ferroelectric liquid crystals (FLC) under different surface anchoring conditions of confining substrates such as high and moderate anchored cells. It is found that the surface effect contributes to the partially unwound helical mode (p-UHM) dielectric process in highly anchored ferroelectric mesogens. Even in the moderately anchored cell, the contribution from p-UHM affects the overall properties of the material. In addition, it is seen that surface mode (p-UHM) is highly dependent on probing alternating electric field (AC) and the p-UHM dielectric process can be suppressed and merged with Goldstone mode (GM) with a high field. However, once the bias field is removed, the surface effect influences the bulk properties (GM) in the sample cell. The depolarizing field due to DC field effect is dominant on the electrode surface of the sample cells in well-aligned FLC samples. This study elucidates the true nature of the GM process under two different surface anchoring conditions of mesogens with AC and DC probing fields at room temperature, which helps in designing advanced FLC-based devices.