Understanding the structural properties and thermal stabilities of Au-Pd-Pt trimetallic clusters

- Structural properties of Au-Pd-Pt clusters are studied by Monte Carlo simulation.
- Melting of Au-Pd-Pt clusters is studied by molecular dynamics simulation.
- Au atoms are systematically segregated on the surface of the Au-Pd-Pt clusters.
- Linear decrease in cluster melting point with the inverse cluster diameter.

In this work, surface segregation phenomena of Au-Pd-Pt trimetallic clusters are investigated by using semi-grand Monte Carlo simulations based on the Gupta potential. It is found that Au atoms are systematically segregated on the surface of the Au-Pd-Pt clusters (6-24 at.% higher than the overall Au concentration), due to the competition among the surface energies of Au, Pd, and Pt. The melting properties of Au-Pd-Pt trimetallic clusters with different composition and size are investigated by using molecular dynamics simulations, based on the same Gupta potential. It is found that the Au-Pd-Pt trimetallic cluster with the highest melting point corresponds to the one with the most stable structure. In addition, linear decrease in cluster melting point with the inverse cluster diameter is predicted for both pure and trimetallic clusters, which is well-known as the Pawlow's law.