Local composition fluctuations act as precursors for crystal nucleation in polydisperse hard spheres

TL;DR

This study investigates how polydispersity influences crystal nucleation in hard spheres, revealing that nucleation preferentially occurs in regions with larger particles and deviates from monodisperse behavior.

Contribution

It demonstrates that polydispersity affects nucleation rates and identifies larger particle regions as precursors, providing new insights into nucleation mechanisms in polydisperse systems.

Findings

Nucleation rate deviates from monodisperse trend with polydispersity.

Larger particles tend to be in regions where nucleation originates.

Nucleation is more likely in regions with higher average particle size.

Abstract

We revisit the effect of polydispersity on the crystal nucleation of hard spheres. Using event-driven molecular dynamics simulations, we obtain the nucleation rate as a function of the supersaturation for a range of polydispersities, and demonstrate that the nucleation rate of polydisperse hard spheres deviates from the trend of monodisperse hard spheres, even when mapped to the effective packing fraction. Furthermore, we show that nucleation tends to originate in regions with on average more larger-sized particles, indicating that such regions act as precursors for nucleation in systems of polydisperse hard spheres.