Phase transitions and characterization in a chiral Smectic-A deVries liquid crystal by low-frequency dielectric spectroscopy

D. M. Potukuchi; A. K. George

doi:10.1080/15421400802221847

Phase transitions and characterization in a chiral Smectic-A _deVries liquid crystal by low-frequency dielectric spectroscopy

D. M. Potukuchi, A. K. George

Physics

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

Low-frequency (10Hz-6.5MHz) dielectric investigations are carried out in Smectic-AdeVr phase exhibited by a chiral Liquid Crystal molecule viz., TSiKN65F. Phase transition temperature determined by dielectric method agrees with TM and DSC. LF dielectric study revealed two relaxations in [image omitted] phase, i.e., a Low-frequency sluggish LF-mode and a High-frequency fast HF-mode of dipole reorientation. Dynamics estimated through slope of [image omitted](T) infers faster HF-mode by three orders. The Arrhenius shift of HF-mode [image omitted] infers an activation energy of 0.72eV. Influence of field on LF mode is studied. Off-centered dielectric dispersion is analyzed through Cole-Davidson equation. Trends of static permittivity (o), high-frequency permittivity (), dielectric increment , and -parameter studied from Cole-Cole plots are explained.

Original language	English
Pages (from-to)	92-109
Number of pages	18
Journal	Molecular Crystals and Liquid Crystals
Volume	487
DOIs	https://doi.org/10.1080/15421400802221847
Publication status	Published - 2008

Keywords

Activation energy
Chiral
De Vries phase
Relaxation
Transition temperature

ASJC Scopus subject areas

Chemistry(all)
Materials Science(all)
Condensed Matter Physics

Access to Document

10.1080/15421400802221847

Cite this

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title = "Phase transitions and characterization in a chiral Smectic-A deVries liquid crystal by low-frequency dielectric spectroscopy",

abstract = "Low-frequency (10Hz-6.5MHz) dielectric investigations are carried out in Smectic-AdeVr phase exhibited by a chiral Liquid Crystal molecule viz., TSiKN65F. Phase transition temperature determined by dielectric method agrees with TM and DSC. LF dielectric study revealed two relaxations in [image omitted] phase, i.e., a Low-frequency sluggish LF-mode and a High-frequency fast HF-mode of dipole reorientation. Dynamics estimated through slope of [image omitted](T) infers faster HF-mode by three orders. The Arrhenius shift of HF-mode [image omitted] infers an activation energy of 0.72eV. Influence of field on LF mode is studied. Off-centered dielectric dispersion is analyzed through Cole-Davidson equation. Trends of static permittivity (o), high-frequency permittivity (), dielectric increment , and -parameter studied from Cole-Cole plots are explained.",

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AU - Potukuchi, D. M.

AU - George, A. K.

PY - 2008

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N2 - Low-frequency (10Hz-6.5MHz) dielectric investigations are carried out in Smectic-AdeVr phase exhibited by a chiral Liquid Crystal molecule viz., TSiKN65F. Phase transition temperature determined by dielectric method agrees with TM and DSC. LF dielectric study revealed two relaxations in [image omitted] phase, i.e., a Low-frequency sluggish LF-mode and a High-frequency fast HF-mode of dipole reorientation. Dynamics estimated through slope of [image omitted](T) infers faster HF-mode by three orders. The Arrhenius shift of HF-mode [image omitted] infers an activation energy of 0.72eV. Influence of field on LF mode is studied. Off-centered dielectric dispersion is analyzed through Cole-Davidson equation. Trends of static permittivity (o), high-frequency permittivity (), dielectric increment , and -parameter studied from Cole-Cole plots are explained.

AB - Low-frequency (10Hz-6.5MHz) dielectric investigations are carried out in Smectic-AdeVr phase exhibited by a chiral Liquid Crystal molecule viz., TSiKN65F. Phase transition temperature determined by dielectric method agrees with TM and DSC. LF dielectric study revealed two relaxations in [image omitted] phase, i.e., a Low-frequency sluggish LF-mode and a High-frequency fast HF-mode of dipole reorientation. Dynamics estimated through slope of [image omitted](T) infers faster HF-mode by three orders. The Arrhenius shift of HF-mode [image omitted] infers an activation energy of 0.72eV. Influence of field on LF mode is studied. Off-centered dielectric dispersion is analyzed through Cole-Davidson equation. Trends of static permittivity (o), high-frequency permittivity (), dielectric increment , and -parameter studied from Cole-Cole plots are explained.

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KW - De Vries phase

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KW - Transition temperature

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