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Collective and Molecular Dielectric Relaxation in Confined Liquid Crystals: Effect of Different Layer Thicknesses and Boundary Conditions

Published online by Cambridge University Press:  01 February 2011

Fouad M. Aliev
Affiliation:
Department of Physics, University of Puerto Rico, San Juan, PR 00931–2343, USA
Manuel Rivera Bengoechea
Affiliation:
Department of Physics, University of Puerto Rico, San Juan, PR 00931–2343, USA
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Abstract

Broadband dielectric spectroscopy was used to study the influence of boundary conditions and layer thickness of liquid crystal (LC) confined to cylindrical pores on low frequency and high frequency relaxation processes. Low frequency measurements provided information on the relaxation of surface polarization that arose at LC – pore wall interface. The dynamics of molecular reorientations were investigated in high frequency experiments. In samples with axial orientation of molecules, the dielectric mode due to reorientation of molecules around their short axis was investigated. The homeotropic alignment of molecules facilitated the investigation of the librational mode. The behavior of this mode was different from the behavior observed in investigations of relaxation due to reorientation of molecules around their short axis. Broadening of the dielectric spectra was observed in confined LC. The broadening increases with decreasing liquid crystal layer thickness.

Type
Research Article
Copyright
Copyright © Materials Research Society 2004

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References

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