Communication: Temperature derivative of the dielectric constant gives access to multipoint correlations in polar liquids

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

Fluctuations of the dipole moment of a macroscopic dielectric sample are induced by thermal motions. The variance of the sample dipole moment, characterizing the extent of thermal fluctuations, is a decaying function of temperature for many polar liquids. This result is inconsistent with the Nyquist (fluctuation-dissipation) theorem predicting the variance of a macroscopic property to grow linearly with temperature. The reason for a qualitatively different behavior is in strong multi-particle correlations of dipolar orientations. An equation connecting the temperature slope of the dielectric constant to a static three-point correlation function is derived. When applied to experimental data for polar and hydrogen-bonding liquids at normal conditions, the three-point correlations of different liquids fall on a single master curve as a function of the dielectric constant. Static three-point correlation functions can potentially reflect the growing spatial correlation length on approach to the glass transition. However, the measured temperature slope of the dielectric constant of glycerol does not indicate a change in such a lengthscale.

Original languageEnglish (US)
Article number041102
JournalJournal of Chemical Physics
Volume144
Issue number4
DOIs
StatePublished - Jan 28 2016

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Communication: Temperature derivative of the dielectric constant gives access to multipoint correlations in polar liquids'. Together they form a unique fingerprint.

  • Cite this