Rigidity and intermediate phases in glasses driven by speciation

TL;DR

This paper investigates how local structural variations influence the rigidity transition and intermediate phase in glasses, using cluster approximations and constraint counting to reveal dependencies on local structure selection.

Contribution

It introduces a model that accounts for local structural variability, showing its impact on the intermediate phase's properties in glass networks.

Findings

The width of the intermediate phase depends on local structure selection.

Networks with flexible units and medium-range order broaden the intermediate phase.

Structural, mechanical, and energetic properties are sensitive to local structural choices.

Abstract

The rigid to floppy transitions and the associated intermediate phase in glasses are studied in the case where the local structure is not fully determined from the macroscopic concentration. The approach uses size increasing cluster approximations and constraint counting algorithms. It is shown that the location and the width of the intermediate phase and the corresponding structural, mechanical and energetical properties of the network depend crucially on the way local structures are selected at a given concentration. The broadening of the intermediate phase is obtained for networks combining a large amount of flexible local structural units and a high rate of medium range order.