Title: Broadband dielectric studies of weakly polar and non-polar liquid crystals
Authors: Oka, A
Sinha, Ghanshyam Prasad
Glorieux, Christ
Thoen, Jan #
Issue Date: Jan-2004
Publisher: Taylor & francis ltd
Series Title: Liquid crystals vol:31 issue:1 pages:31-38
Abstract: Complex dielectric permittivities, for two orientations of the director n, parallel ( E || n) and perpendicular (E perpendicular to n) to the probing electric field E, of the weakly polar liquid crystals (LCs) 4,4'-dihexylazoxybenzene (D6AOB) and 4,4'-diheptylazoxybenzene (D7AOB) as well as the non-polar LC diheptylazobenzene (D7AB) have been measured in the frequency range 75 kHz to 1 GHz. The measurements were performed in the nematic, smectic and isotropic phases of the LCs. The dielectric anisotropies Deltaepsilon (=epsilon||-epsilonperpendicular to) obtained from the values of dielectric permittivities at 100 kHz in the nematic phase were found to increase with decreasing temperature. However, for the DnAOBs, the Deltaepsilon values are somewhat smaller than that for D7AB which does not have a permanent dipole moment. In the nematic phase two molecular relaxation processes were observed for both DnAOBs in each of the orientations parallel and perpendicular. The four processes merge into two separate processes in the isotropic phase. For D7AB no orientational relaxations were observed in the experimental frequency range.
ISSN: 0267-8292
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Soft Matter and Biophysics
# (joint) last author

Files in This Item:

There are no files associated with this item.

Request a copy


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science