Structure, stability, and surface diffusion of clusters: Pt4/Cu (110) AND Au4/Ag (110) surface by molecular dynamics

In this work, molecular dynamics simulations have been used to simulate the behavior of tetramer clusters behavior in Pt4 /Cu (110) and Au4 /Ag (110) systems, in the temperature range 300-600 K. All activation barriers and formation energies related to different tetramer shapes (4S, 4L, 4T, 4N and 4l) have been calculated by embedded atom method (EAM) at static regime (0 K). From an energetical point of view, the adatoms tend to diffuse via simple jumps and exchange mechanisms leading to a transition between all forms during tetramer diffusion. Statistical analysis after molecular dynamics simulations confirms that the linear 4l shape is more stable and needs high energy to be disintegrated in both systems. The lifetime study of each shape for different temperatures (from 300 K to 600 K) proves that the 4 l form is more stiff, which is in a good agreement with the formation energy predictions.