Johari-Goldstein relaxation in glass-electrets

TL;DR

This study explores how the dielectric response of dipolar glass-forming materials changes in the glass-electret state, revealing an increased Johari-Goldstein relaxation strength, which informs the microscopic understanding of glassy dynamics.

Contribution

It demonstrates the modification of Johari-Goldstein relaxation in glass-electrets, providing new insights into the microscopic mechanisms of glassy relaxation phenomena.

Findings

Increased Johari-Goldstein relaxation strength in glass-electrets

Modification of dielectric response in the glass-electret state

Implications for microscopic interpretation of glass relaxation

Abstract

We investigate the dielectric response in the glass-electret state of two dipolar glass-forming materials. This unusual polar glassy state of matter is produced when a dipolar liquid is supercooled under the influence of a high electric dc field, which leads to partial orientational order of the molecules carrying a dipole moment. Investigation of the prepared glass-electrets by using low-field dielectric spectroscopy reveals a clear modification of their dielectric response in the regime of the Johari-Goldstein beta-relaxation, pointing to a small but significant increase of its relaxation strength compared to the normal glass. We discuss the implications of this finding for the still controversial microscopic interpretation of the Johari-Goldstein relaxation, an inherent property of glassy matter.