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Proceedings Paper

Investigation of relaxation processes in MHPB(H)PBC antiferroelectric liquid crystal by dielectric spectroscopy
Author(s): M. B. Pandey; Roman Dabrowski; V. K. Agrawal; R. Dhar
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Paper Abstract

The molecular dynamics of a recently synthesized chiral antiferroelectric liquid crystal (S)-(+)-4-(1-methylheptyloxycarbonyl)phenyl-4'-(3-butanoiloxyprop-1-oxy)biphenyl-4'-carboxylate (in short MHPB(H)PBC) exhibiting SmA* and SmCA* phases have been studied in the frequency range of 1 Hz to 10 MHz. In the SmA* phase only one doubly degenerate soft mode relaxation exists which becomes critical at transition temperature and its splits into two modes in SmCA* phase, one at high frequency about 500 kHz, the other at low frequency about 40 kHz. Relaxation frequencies of both modes decrease slowly with decrease in temperature. These two observed modes are due to the anti-phase and in-phase azimuthal angle fluctuations of the molecules in the anti-tilt pairs. The temperature dependence of the dielectric strengths and relaxation frequencies, determined by Cole-Cole plot clearly reveals that SmA* to SmCA* transition is weakly first order.

Paper Details

Date Published: 1 September 2004
PDF: 6 pages
Proc. SPIE 5565, XV Conference on Liquid Crystals, (1 September 2004); doi: 10.1117/12.581073
Show Author Affiliations
M. B. Pandey, Ewing Christian College (India)
Roman Dabrowski, Military Univ. of Technology (Poland)
V. K. Agrawal, Univ. of Allahabad (India)
R. Dhar, Ewing Christian College (India)


Published in SPIE Proceedings Vol. 5565:
XV Conference on Liquid Crystals
Jozef Zmija, Editor(s)

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