Ternary alloying effect on the melting of metal clusters

Canonical ensemble Monte Carlo simulations are applied to investigate the melting of the icosahedral 55-atom Ag-Cu-Au clusters. The clusters are modeled by the second-moment approximation of the tight-binding (TB-SMA) many-body potentials. Results show that the introduction of the only Cu atom of the third alloying metal in the bimetallic Ag₄₃Au₁₂ cluster, forming the Ag₄₂Cu₁Au₁₂ cluster, can greatly increase the melting point of the cluster by about 100 K. It is also found that the substitution of the only Cu atom of the third alloying metal in the Ag₁Au₅₄ clusters, forming the Ag₁Cu₁Au₅₃ cluster, can result in an increase of 40 K in the melting point. It can be concluded that the melting points of the bimetallic clusters can be tuned by the third metal impurities doping. In addition, the surface segregation of Ag atoms in the Ag-Cu-Au trimetallic clusters occurs even after melting.