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

D. M. Potukuchi, A. K. George

Research output: Contribution to journalArticle

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 languageEnglish
Pages (from-to)92-109
Number of pages18
JournalMolecular Crystals and Liquid Crystals
Volume487
DOIs
Publication statusPublished - 2008

Fingerprint

Liquid Crystals
Dielectric spectroscopy
Liquid crystals
Phase transitions
liquid crystals
low frequencies
Permittivity
spectroscopy
permittivity
Superconducting transition temperature
Activation energy
retraining
plots
Molecules
transition temperature
slopes
dipoles
activation energy
trends
shift

Keywords

  • Activation energy
  • Chiral
  • De Vries phase
  • Relaxation
  • Transition temperature

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

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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.

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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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