Computational study on thermal stability of an AuCu249 alloy cluster on the atomic scale

Structural change of an AuCu intermetallic alloy cluster including 249 atoms during heating is studied by molecular dynamics simulation within the framework of embedded atom method. The analyses of pair-distribution function, atomic density function, and pair analysis technique show that the structural change of this cluster involves different stages from the outer part into the inner part owing to continuously interchanging positions among atoms at elevated temperature. During the change of the atom packing structure, gold atoms move from the inner part to the outer part of this cluster, whereas copper atoms move from the outer part into the inner part.