Heterogeneous nucleation of/on nanoparticles: a density functional study using the phase-field crystal model

TL;DR

This paper uses the phase-field crystal model to study how heterogeneous nucleation occurs on nanoparticles, revealing the importance of lattice mismatch and the dynamic nature of nucleation pathways for material design.

Contribution

It demonstrates the application of a density functional theory approach to understand precursor-mediated nucleation and the effects of lattice mismatch on nucleation barriers.

Findings

Lattice mismatch influences contact angle and nucleation barrier non-monotonically.

Time-dependent studies reveal preferred nucleation pathways.

Modeling aids in designing materials with controlled nucleation.

Abstract

Crystallization of supersaturated liquids usually starts by heterogeneous nucleation. Mounting evidence shows that even homogeneous nucleation in simple liquids takes place in two steps; first a dense amorphous precursor forms, and the crystalline phase appears via heterogeneous nucleation in/on the precursor cluster. Herein, we review recent results by a simple dynamical density functional theory, the phase-field crystal model, for (precursor-mediated) homogeneous and heterogeneous nucleation of nanocrystals. It will be shown that the mismatch between the lattice constants of the nucleating crystal and the substrate plays a decisive role in determining the contact angle and nucleation barrier, which were found to be non-monotonic functions of the lattice mismatch. Time dependent studies are essential as investigations based on equilibrium properties often cannot identify the preferred nucleation pathways. Modeling of these phenomena is essential for designing materials on the basis of controlled nucleation and/or nano-patterning.