Static, transient, and dynamic phase coexistence in metal nanoclusters

Area of Science:

• Materials Science
• Computational Chemistry
• Nanotechnology

Background:

• Understanding phase transitions in nanoscale materials is crucial for their application.
• Coexistence of solid and liquid phases in metal clusters presents unique thermodynamic properties.
• Previous studies have explored melting points and phase behavior in small metal clusters.

Purpose of the Study:

• To investigate the phenomenon of static and dynamic phase coexistence in silver, copper, and nickel clusters.
• To determine the critical cluster sizes at which static coexistence emerges.
• To characterize the nature of phase coexistence in clusters smaller than the static coexistence threshold.

Main Methods:

• Utilized molecular dynamics simulations to model the behavior of metal clusters.
• Analyzed atomic configurations and energy profiles to identify solid and liquid phases.
• Examined cluster sizes ranging from small nanoparticles to larger assemblies.

Main Results:

• Identified static coexistence of solid and liquid phases in 561-atom copper and silver icosahedra, and 923-atom nickel icosahedra.
• Observed static coexistence in clusters exceeding these specific sizes.
• Found that smaller clusters typically exhibit dynamic coexistence (solid-liquid or solid-solid-liquid transitions) rather than static coexistence.

Conclusions:

• Cluster size is a critical factor determining the type of phase coexistence in metal nanoparticles.
• Static phase coexistence is established above specific size thresholds for silver, copper, and nickel clusters.
• Dynamic and transient coexistence are characteristic of smaller metal clusters, highlighting size-dependent melting behaviors.