Diffusive redistribution of small spheres in crystallization of highly asymmetric binary hard-sphere mixtures

TL;DR

This study uses molecular dynamics simulations to explore how small spheres diffuse and redistribute during the crystallization of large spheres in asymmetric binary hard-sphere mixtures, revealing their influence on crystallization kinetics.

Contribution

It provides direct evidence linking the diffusive redistribution of small spheres to the crystallization process of large spheres in highly asymmetric mixtures.

Findings

Small spheres' density profiles change during crystallization stages.

Small spheres' redistribution closely relates to crystal growth.

Addition of small spheres does not alter the crystal structure.

Abstract

We report a molecular dynamics study of crystallization in highly asymmetric binary hard-sphere mixtures, in which the large spheres can form a crystal phase while the small ones remain disordered during the crystallization process of the large spheres. By taking advantage of assisting crystal nucleation with a patterned substrate, direct evidence is presented that there is a close link between the diffusive redistribution of the small spheres and the crystal formation of the large spheres. Although the addition of a second component with large size disparity will not alter the crystal structure formed by the large spheres, the density profile of the small spheres displays corresponding changes at different crystallization stages and closely relates to the crystal growth, suggesting possible effect of small spheres on the crystallization kinetics.