Time-resolved non-linear dielectric responses in molecular systems

Ranko Richert, Wei Huang

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Impedance measurements in the 0.1 Hz to 50 kHz range are performed beyond the linear response regime, using a technique where peak fields as high as 450 kV/cm are possible. The main focus is on the effects of the energy that is transferred irreversibly from the external field to a molecular glass-forming liquid. Because the slow degrees of freedom absorb this energy, their heterogeneous configurational temperatures are increased before the heat is transferred to the phonons on the time scale of structural relaxation. We also discuss a time-resolved variant of high-field impedance spectroscopy, where the harmonic field is applied for a number of cycles at a low field, followed by the same signal at a much higher field. Fourier analysis of the resulting voltage and current traces provides a period-by-period time-resolved picture for the response of the configurational temperature with a 5 mK resolution, resulting from a sensitivity on the 5 × 10-5 level for tan δ. It turns out that this energy absorption is responsible for an extremely pronounced non-linearity in the electric field, where the dielectric relaxation can be accelerated by a factor of 2 prior to changing the temperature.

Original languageEnglish (US)
Pages (from-to)787-793
Number of pages7
JournalJournal of Non-Crystalline Solids
Volume356
Issue number11-17
DOIs
StatePublished - Apr 1 2010

Fingerprint

Structural relaxation
Fourier analysis
Dielectric relaxation
impedance measurement
energy absorption
Energy absorption
Phonons
Temperature
temperature
phonons
degrees of freedom
nonlinearity
Electric fields
Spectroscopy
impedance
harmonics
Glass
heat
cycles
electric fields

Keywords

  • Dielectric properties
  • Electric modulus
  • Glass transition
  • Relaxation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials
  • Materials Chemistry

Cite this

Time-resolved non-linear dielectric responses in molecular systems. / Richert, Ranko; Huang, Wei.

In: Journal of Non-Crystalline Solids, Vol. 356, No. 11-17, 01.04.2010, p. 787-793.

Research output: Contribution to journalArticle

@article{51d311e852f942f38c879c7e61698b51,
title = "Time-resolved non-linear dielectric responses in molecular systems",
abstract = "Impedance measurements in the 0.1 Hz to 50 kHz range are performed beyond the linear response regime, using a technique where peak fields as high as 450 kV/cm are possible. The main focus is on the effects of the energy that is transferred irreversibly from the external field to a molecular glass-forming liquid. Because the slow degrees of freedom absorb this energy, their heterogeneous configurational temperatures are increased before the heat is transferred to the phonons on the time scale of structural relaxation. We also discuss a time-resolved variant of high-field impedance spectroscopy, where the harmonic field is applied for a number of cycles at a low field, followed by the same signal at a much higher field. Fourier analysis of the resulting voltage and current traces provides a period-by-period time-resolved picture for the response of the configurational temperature with a 5 mK resolution, resulting from a sensitivity on the 5 × 10-5 level for tan δ. It turns out that this energy absorption is responsible for an extremely pronounced non-linearity in the electric field, where the dielectric relaxation can be accelerated by a factor of 2 prior to changing the temperature.",
keywords = "Dielectric properties, Electric modulus, Glass transition, Relaxation",
author = "Ranko Richert and Wei Huang",
year = "2010",
month = "4",
day = "1",
doi = "10.1016/j.jnoncrysol.2009.08.047",
language = "English (US)",
volume = "356",
pages = "787--793",
journal = "Journal of Non-Crystalline Solids",
issn = "0022-3093",
publisher = "Elsevier",
number = "11-17",

}

TY - JOUR

T1 - Time-resolved non-linear dielectric responses in molecular systems

AU - Richert, Ranko

AU - Huang, Wei

PY - 2010/4/1

Y1 - 2010/4/1

N2 - Impedance measurements in the 0.1 Hz to 50 kHz range are performed beyond the linear response regime, using a technique where peak fields as high as 450 kV/cm are possible. The main focus is on the effects of the energy that is transferred irreversibly from the external field to a molecular glass-forming liquid. Because the slow degrees of freedom absorb this energy, their heterogeneous configurational temperatures are increased before the heat is transferred to the phonons on the time scale of structural relaxation. We also discuss a time-resolved variant of high-field impedance spectroscopy, where the harmonic field is applied for a number of cycles at a low field, followed by the same signal at a much higher field. Fourier analysis of the resulting voltage and current traces provides a period-by-period time-resolved picture for the response of the configurational temperature with a 5 mK resolution, resulting from a sensitivity on the 5 × 10-5 level for tan δ. It turns out that this energy absorption is responsible for an extremely pronounced non-linearity in the electric field, where the dielectric relaxation can be accelerated by a factor of 2 prior to changing the temperature.

AB - Impedance measurements in the 0.1 Hz to 50 kHz range are performed beyond the linear response regime, using a technique where peak fields as high as 450 kV/cm are possible. The main focus is on the effects of the energy that is transferred irreversibly from the external field to a molecular glass-forming liquid. Because the slow degrees of freedom absorb this energy, their heterogeneous configurational temperatures are increased before the heat is transferred to the phonons on the time scale of structural relaxation. We also discuss a time-resolved variant of high-field impedance spectroscopy, where the harmonic field is applied for a number of cycles at a low field, followed by the same signal at a much higher field. Fourier analysis of the resulting voltage and current traces provides a period-by-period time-resolved picture for the response of the configurational temperature with a 5 mK resolution, resulting from a sensitivity on the 5 × 10-5 level for tan δ. It turns out that this energy absorption is responsible for an extremely pronounced non-linearity in the electric field, where the dielectric relaxation can be accelerated by a factor of 2 prior to changing the temperature.

KW - Dielectric properties

KW - Electric modulus

KW - Glass transition

KW - Relaxation

UR - http://www.scopus.com/inward/record.url?scp=77349110242&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77349110242&partnerID=8YFLogxK

U2 - 10.1016/j.jnoncrysol.2009.08.047

DO - 10.1016/j.jnoncrysol.2009.08.047

M3 - Article

AN - SCOPUS:77349110242

VL - 356

SP - 787

EP - 793

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

SN - 0022-3093

IS - 11-17

ER -