Growth pathways of Cu shells on Au and AuCu seeds: interdiffusion, shape transformations, strained shells and patchy...

Prior research has shown that nanoparticle growth often depends on seed composition and temperature. Established methods focus on uniform shell formation, but less is known about how mixed-metal seeds influence growth outcomes. This gap motivated the exploration of Cu deposition on Au and AuCu seeds. No prior work had resolved how interdiffusion and surface strain affect shell morphology. Understanding these factors could expand nanoparticle design possibilities. Molecular dynamics simulations offer a way to track atomic-scale transformations. This study builds on existing knowledge of metal diffusion and cluster formation. It aims to clarify how seed shape and composition influence growth pathways.

The aim is to investigate how Cu atoms deposit on Au and AuCu nanoparticle seeds to form new structures. The specific problem is understanding how seed composition and temperature affect growth outcomes. This study focuses on structural transformations during Cu deposition. The motivation is to identify growth mechanisms that produce non-uniform surfaces. The authors propose that surface and bulk diffusion processes regulate these transformations. They seek to determine how interdiffusion and dewetting influence final structures. The goal is to provide a framework for designing nanoparticles with tailored surface arrangements. These findings could support applications in catalysis and materials science.

Molecular dynamics simulations model Cu deposition on Au and AuCu seeds. The simulations track atomic movements at different growth temperatures. Seed shapes and compositions are varied to observe growth outcomes. Surface diffusion and bulk diffusion processes are analyzed in detail. The study examines structural transitions between different nanoparticle motifs. Dewetting phenomena are identified as a key factor in surface transformations. Interdiffusion between Au and Cu atoms is monitored during growth. The simulations provide insights into how strain and composition affect shell formation.

Cu deposition on Au seeds produces core@shell structures and Janus-like arrangements. Mixed AuCu seeds lead to patchy surfaces and shape transformations. Growth temperature influences the extent of interdiffusion and surface strain. Surface diffusion dominates at lower temperatures, while bulk diffusion increases at higher temperatures. Dewetting occurs when Cu atoms cluster on one side of the seed. The simulations reveal that strain in Cu shells drives structural reorganization. Surface atom arrangements differ significantly between Au and AuCu seeds. These results suggest that Cu deposition can create nanoparticles with non-uniform surfaces.

The authors propose that Cu deposition on Au and AuCu seeds leads to diverse growth outcomes. Structural transformations depend on seed composition and growth temperature. Surface and bulk diffusion processes regulate these transformations. Dewetting and interdiffusion are key mechanisms in shell formation. The study shows that Cu deposition can produce nanoparticles with patchy surfaces. These structures may be of interest for catalytic applications. The findings suggest that growth conditions can be tuned to control surface arrangements. The authors emphasize the potential of Cu@Au and Cu@AuCu structures for functional materials.