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

被引:5
作者
Chandran, Achu [1 ,2 ]
Choudhary, Amit [3 ]
Gangwar, Lokesh K. [2 ,4 ]
Abhilash, T. K. [1 ,2 ]
Athira, B. S. [1 ,2 ]
Biradar, A. M. [2 ,4 ]
机构
[1] CSIR Natl Inst Interdisciplinary Sci & Technol NI, Mat Sci & Technol Div, Thiruvananthapuram 695019, Kerala, India
[2] Acad Sci & Innovat Res AcSIR, CSIR HRDC, Ghaziabad 201002, Uttar Pradesh, India
[3] Univ Delhi, Phys Dept, Deshbandhu Coll, New Delhi 110019, India
[4] CSIR Natl Phys Lab, Dr KS Krishnan Marg, New Delhi 110012, India
关键词
Ferroelectric Liquid Crystals; Surface anchoring; Partially unwound helical mode; Goldstone Mode; Dielectric Relaxation; FREQUENCY DIELECTRIC-RELAXATION; LAYER STRUCTURE; CELL THICKNESS; ALIGNMENT; DEPENDENCE; MIXTURES; DESIGN;
D O I
10.1016/j.molliq.2021.117194
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
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. (C) 2021 Elsevier B.V. All rights reserved.
引用
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页数:6
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