High-frequency dynamics of type-B glass formers investigated by broadband dielectric spectroscopy

TL;DR

This study uses broadband dielectric spectroscopy to explore high-frequency dynamics in type-B glass formers, revealing a fast beta-process and analyzing it within the mode-coupling theory framework.

Contribution

It provides new insights into the fast beta-process in glass formers by extending spectral analysis up to 1 THz and applying mode-coupling theory.

Findings

Identification of a fast beta-process in the high-frequency loss minimum.

Extension of spectral analysis up to 1 THz.

Evidence supporting mode-coupling theory in describing the fast process.

Abstract

We present the results of broadband dielectric spectroscopy on two glass formers with strong Johari-Goldstein beta-relaxations. In addition to the alpha- and beta-relaxation dynamics, the extension of the spectra up to 1 THz also allows revealing information on the fast beta-process in this class of materials. There is clear evidence for a fast process contributing in the region of the high-frequency loss minimum, which is analyzed in terms of the idealized mode-coupling theory.