Eshelby description of highly viscous flow -- half model, half theory

TL;DR

This paper extends the Eshelby transition model to include reversible processes, providing a comprehensive theoretical framework for understanding highly viscous flow in undercooled liquids, and addresses several open questions in the field.

Contribution

It introduces a unified model incorporating reversible and irreversible Eshelby transitions, with the Kohlrausch exponent as a key parameter, advancing the theoretical understanding of viscous flow.

Findings

The model explains the role of reversible transitions in viscous flow.

It accounts for the Kohlrausch relaxation behavior with a free exponent.

The approach resolves longstanding open questions about the microscopic mechanisms.

Abstract

A recent description of the highly viscous flow ascribes it to irreversible thermally activated Eshelby transitions, which transform a region of the undercooled liquid to a different structure with a different elastic misfit to the viscoelastic surroundings. The description is extended to include reversible Eshelby transitions, with the Kohlrausch exponent $\beta$ as a free parameter. The model answers several open questions in the field.