Mechanical disorder of sticky-sphere glasses. II. Thermo-mechanical inannealability

TL;DR

This study investigates how the mechanical properties of sticky-sphere glasses change with thermal annealing, revealing that increased stickiness suppresses certain stiffening effects and leads to thermo-mechanical inannealability.

Contribution

It demonstrates that the degree of stickiness in glasses determines their response to thermal annealing, introducing the concept of thermo-mechanical inannealability in very sticky glasses.

Findings

Elastic properties depend on glass 'stickiness'

Stiffening of shear modulus is suppressed in sticky glasses

Soft quasilocalized modes become invariant to annealing in sticky glasses

Abstract

Many structural glasses feature static and dynamic mechanical properties that can depend strongly on glass formation history. The degree of universality of this history-dependence, and what it is possibly affected by, are largely unexplored. Here we show that the variability of elastic properties of simple computer glasses under thermal annealing depends strongly on the strength of attractive interactions between the glasses' constituent particles -- referred to here as glass `stickiness'. We find that in stickier glasses the stiffening of the shear modulus with thermal annealing is strongly suppressed, while the thermal-annealing-induced softening of the bulk modulus is enhanced. Our key finding is that the characteristic frequency and density per frequency of soft quasilocalized modes becomes effectively invariant to annealing in very sticky glasses, the latter are therefore deemed `thermo-mechanically inannealable'. The implications of our findings and future research directions are discussed.