Crystal Nucleation in a Supercooled Liquid with Glassy Dynamics

TL;DR

This study investigates crystal nucleation in supercooled silica, revealing how glassy dynamics and the breakdown of the Stokes-Einstein relation influence the liquid's crystallization limit and its relation to the Kauzmann temperature.

Contribution

It demonstrates that glassy dynamics set a fundamental limit on supercooled liquid stability and links the homogeneous nucleation limit to the breakdown of the Stokes-Einstein relation.

Findings

Crystallization occurs faster than equilibration below the HNL.

The HNL would be lower or absent if the Stokes-Einstein relation held.

Glassy dynamics are central to the crystallization limit.

Abstract

In simulations of supercooled, high-density liquid silica we study a range of temperature T in which we find both crystal nucleation, as well as the characteristic dynamics of a glass forming liquid, including a breakdown of the Stokes-Einstein relation. We find that the liquid cannot be observed below a homogeneous nucleation limit (HNL) at which the liquid crystallizes faster than it can equilibrate. We show that the HNL would occur at lower T, and perhaps not at all, if the Stokes-Einstein relation were obeyed, and hence that glassy dynamics plays a central role in setting a crystallization limit on the liquid state in this case. We also explore the relation of the HNL to the Kauzmann temperature, and test for spinodal-like effects near the HNL.