Uncovering the effects of interface-induced ordering of liquid on crystal growth using machine learning

TL;DR

This paper uses atomistic simulations and machine learning to reveal how interface-induced ordering in liquids affects atomic mobility and crystal growth rates, providing a new understanding of crystallization kinetics.

Contribution

It demonstrates that interface-induced ordering significantly impacts liquid mobility and crystal growth, with a novel machine learning approach quantifying this effect across different materials.

Findings

Interface-induced ordering reduces atomic mobility near interfaces.

The extent of mobility reduction varies with interface type and ordering degree.

Incorporating IIO effects improves crystal growth rate predictions.

Abstract

The process of crystallization is often understood in terms of the fundamental microstructural elements of the crystallite being formed, such as surface orientation or the presence of defects. Considerably less is known about the role of the liquid structure on the kinetics of crystal growth. Here atomistic simulations and machine learning methods are employed together to demonstrate that the liquid adjacent to solid-liquid interfaces presents significant structural ordering, which effectively reduces the mobility of atoms and slows down the crystallization kinetics. Through detailed studies of silicon and copper we discover that the extent to which liquid mobility is affected by interface-induced ordering (IIO) varies greatly with the degree of ordering and nature of the adjacent interface. Physical mechanisms behind the IIO anisotropy are explained and it is demonstrated that incorporation of this effect on a physically-motivated crystal growth model enables the quantitative prediction of the growth rate temperature dependence.