Energetics and heterodiffusion of Cu on Ag(110) stepped surfaces

Abstract

A molecular-dynamics simulation study has been performed to investigate the Cu adatom diffusion on the (110) stepped surfaces of Ag, using interatomic potentials described by the embedded atom method. We have systematically calculated the energy barriers for different possible diffusion mechanisms, which occur on the terrace and near the step edge. Our findings show that the predominant atomistic diffusion process at step edge and on the terrace is the exchange mechanism with anES barrier about 220 meV lower than that via jumping (290 meV), indicating that the incorporation of Cu adatom into Ag (110) is 'easier' than making a jump on the surface. On the other hand, the calculation of the Ehrlich-Schwoebel (ES) barrier demonstrates that this quantity is equal to 0 meV for the exchange process near the step edge and about 60 meV for channel-channel migration. Thus, the mass transport across steps may be important due to the lack of the ES barriers for exchange mechanism, revealing the possible layer-by-layer growth mode for our heterogeneous system.

Numerical study of self‐ and heterodiffusion on clean unreconstructed and missing‐row reconstructed Pt(110) surfaces

“…The EAM has been used successfully to study the heteroadsorption and diffusion on (110) and (100) surfaces , and it is validated by checking its results for diffusion barriers on the (100) surface against density‐functional theory (DFT), and it is applied again to investigate the adsorption and diffusion of Pt and Au adatoms on the different missing‐row configurations of the (110) surface for homogeneous and heterogeneous systems.…”