The role of local bond-order at crystallization in a simple supercooled liquid

TL;DR

This study uses large-scale molecular dynamics simulations to explore how local bond-order influences crystallization in supercooled Lennard-Jones liquids, revealing heterogeneous structures and rapid crystallization processes.

Contribution

It demonstrates the role of high local bond-order regions in initiating and supporting fast crystallization in supercooled liquids, highlighting heterogeneity and polycrystalline formations.

Findings

Supercooled states contain regions with higher bond-order than average.

Crystallization begins in high bond-order regions with specific bond-order signatures.

Crystallization is rapid and often results in polycrystalline structures with fcc and hcp arrangements.

Abstract

Large scale Molecular Dynamics simulations of sixty-five systems with N=80000 Lennard-Jones particles at two different supercooled liquid state points reveals, that the supercooled states contain spatially heterogeneous distributed subdomains of particles with significant higher bond-order than the mean bond-order in the supercooled liquid. The onset of crystallization starts in such an area with relative high six-ford bond-order for a supercooled state, but low bond-order for a fcc crystal. The critical nucleus of N \approx 70 particles is surrounded by many hundred of particles with relative high supercooled liquid bond-order and many of these particles are aligned with the crystal ordered particles in the critical nucleus. The crystallizations are very fast and supported by a fast growth of the supercooled areas with relative high liquid bond-order. The crystallization are to fcc crystals, but with significant part of the crystallizations exhibit five fold arrangements of polycrystalline subdomains mainly with fcc crystal order and sign of hcp crystallites.