Retardation and flow at the glass transition

TL;DR

This paper models the transition from reversible jumps to irreversible flow at the glass transition using an ensemble of double-well potentials characterized by the Kohlrausch exponent, applied to shear and dielectric data.

Contribution

It introduces a model linking microscopic jump dynamics to macroscopic flow behavior at the glass transition, incorporating the Kohlrausch exponent.

Findings

The model successfully describes shear and dielectric data.

It captures the crossover from reversible to irreversible jumps.

Provides insights into the microscopic mechanisms of glass transition.

Abstract

The crossover from back-and-forth jumps between structural minima to the no-return jumps of the viscous flow is modeled in terms of an ensemble of double-well potentials with a finite decay probability. The ensemble is characterized by the Kohlrausch-exponent $\beta$ of the time dependence $t^\beta$ of the response at short times. The model is applied to shear and dielectric data from the literature.