Atomistic investigation of coarsening kinetics of supported nanoparticles using the phase field crystal model

Abstract

The coarsening of supported nanoparticles is an inevitable process that has a significant impact on the properties of materials. However, due to the limitation of experimental techniques, the atomistic kinetic mechanisms of coarsening remain largely unknown. In this work, we simulated the coarsening process of supported nanoparticles using the phase-field crystal (PFC) model in 2D and examined the influence of substrates' lattice structure on the kinetics of coarsening. The simulation results show that the particle size distribution (PSD) is consistent with mean field methods for the coarsening of triangular structured particles on the fcc(111) face, while the PSD is of a log-normal type for the coarsening on the fcc(110) and fcc(100) faces, which is consistent with the contact model of coarsening. The coarsening of supported nanoparticles is diffusion controlled, and the order of coarsening rate is K₍₁₁₁₎ > K₍₁₁₀₎ > K₍₁₀₀₎. Also, we investigated the influence of lattice mismatch on the coarsening process and found that the coarsening rate decreases with the lattice mismatch. In addition, we observed a superlattice on the surface of the particles using the PFC model, which is similar to previous experimental results, and analyzed the effect of the superlattice on the coarsening of the nanoparticles.