Adatom binding energies of Cu atoms on the (111) surface of Cu/Ag nanofilms

Abstract

The focus of this study is on how the composition of Cu/Ag nanofilms affects the surface interactions. The adatom binding energies of Cu atoms on the (111) surface of Cu/Ag nanofilms are also examined. Molecular dynamics (MD) simulations reveal that the binding energy of Cu adatoms varies significantly with alloy concentration. This research uncovers a non-linear relationship between binding energy and alloy composition, with optimal surface binding occurring at a 28% Ag content. Cu/Ag nanofilms with less than 64% Ag content exhibited enhanced adatom binding energies compared to that of pure Cu. The binding energy at specific alloy concentrations depends on the nearest neighbor configurations of Cu and Ag atoms beneath the adatom. The hypergeometric probability distribution and clustering techniques are used to successfully distinguish between various nearest neighbor configurations. Deviations between the computational results and probability theory demonstrate that Cu adatoms tend to bond more closely with Cu surface atoms than with Ag surface atoms, skewing adatoms away from the expected FCC and HCP bonding sites.