Kinetic Fragility Directly Correlates with the Many-body Static Amorphous Order in Glass-Forming Liquids

TL;DR

This paper demonstrates a direct correlation between kinetic fragility and many-body static amorphous order in glass-forming liquids, suggesting structural origins of dynamical slowing down near the glass transition.

Contribution

It provides evidence linking static amorphous order to fragility, advancing understanding of the structural basis of glassy dynamics.

Findings

Growing static amorphous order correlates with fragility.

Dynamical response is encoded in micro-structures.

Insights may explain temperature dependence of relaxation times.

Abstract

The term "fragility" describes the rate at which viscosity grows when a supercooled liquid approaches its putative glass transition temperature. The field of glassy materials is actively searching for a structural origin that governs this dynamical slowing down in the supercooled liquid, which occurs without any discernible change in structure. Our work shows clear evidence that growing many-body static amorphous order is intimately correlated with the kinetic fragility of glass-forming liquids. It confirms that the system's dynamical response to temperature is concealed in its micro-structures. This finding may pave the way for a deeper understanding of the different temperature dependence of the relaxation time or viscosity in a wide variety of glass-forming liquids.