Khan, Sidra and Prakash, Jai and Chauhan, Shikha and Choudhary, Amit and Biradar, A. M. (2020) Partially unwound helical mode in surface stabilized ferroelectric liquid crystal geometry. Journal of Molecular Liquids, 305. pp. 112767-112777. ISSN 0167-7322

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Abstract

We report the dielectric relaxation spectroscopy and textural observations in surface stabilized ferroelectric liquid crystal (FLC) (SSFLC), having thickness less than the pitch value of the FLC and non-SSFLC geometries, having thickness of sample cell more than the pitch value of same FLC material, namely SCE-13 to get a deeper understanding of the helicoidal structure at the surface of bounding substrate. In SSFLC sample cell, the surface boundaries of cell allow stronger surface forces to align molecules parallel to the substrate and resultant helix becomes unwound. In non-SSFLC cell, the boundary effect is slightly weaker than in SSFLC and hence the helical structure is slightly unwound at the interface of the substrate and FLC; whereas in bulk the helix is naturally wound. The suppression of helix in SSFLC state has resulted in distinct and sharp partial relaxation peaks of unwound helical mode (p-UHM) whereas in non-SSFLC cells no p-UHM relaxation peak is observed. The p-UHM process is highly dependent on the applied oscillating voltage above the threshold voltage of 300 mV, whereas the dependence of well-established Goldstone mode is negligible. Furthermore, textural observations in SSFLC state have shown three molecular orientations, whereas in non-SSFLC cells, optical textures are multi domain planar-aligned. The underlying studies will give fundamental insights into the SSFLC and non-SSFLC structures which in turn pave a way towards the fabrication of high-performance futuristic electro-optical devices.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier.
Subjects:	Chemistry Cell Biology > Molecular Physics > Atomic and Molecular Physics Physical Chemistry/Chemical Physics
Divisions:	UNSPECIFIED
Depositing User:	Mr. Yogesh Joshi
Date Deposited:	08 Apr 2022 05:56
Last Modified:	08 Apr 2022 05:56
URI:	http://npl.csircentral.net/id/eprint/4844

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