Atomic Scale Calculations Of The Thermal Stability Of Bimetallic Clusters Au_xCu_y(x+y=57)with Core-Shell Structures

Bimetallic nanoparticles with core-shel structures have attracted much attention because of their atomic packing structures and unusual properties. These particles have been applied in many fields, especially in the field of catalysis. Today, much research has been paid to the nano-materials with core-shell structures, especially for the metal@metal (ie. bimetallic materials with core-shell structures) owing to their great potential applications as catalysts. As model alloys, the Au-Cu nano-alloys have been intensively studied from materials, physics, and chemistry scientists. The study to the core-shell structures is helpful in revealing the evolution from single atoms or molecules to condensed matter, and it provides the scientific basis for materials design and the improvement of materials properties.In this paper, the microstructural changes are calculated by molecular dynamics (MD) simulations within the framework of embedded atom method (EAM) for the Au@Cu, and Cu@Au clusters containing57atoms with calculations of atomic average energy, atom pack structure, pair distribution functions, atomic density profiles, and mean square displacement futions, it is found that the structural change patterns are different for the clusters have different initial structures at elevated temperature. The Cu43Au14cluster is the most stable.