DIFFUSION OF CN ON CU SURFACES

Diffusion of a single Cu adatom on low-index Cu surfaces with differen t morphologies (with and without the presence of other Ca adatoms as w ell as near and over stepped surfaces) is studied using the embedded-a tom method and a molecular static simulation. Migration energies of a Cu adatom in the presence of other Cu adatoms which are relevant in co mputer simulations of island growth are calculated. We have also calcu lated the formation and migration energies of an adatom and a vacancy in different layers as well as formation energies of steps on various Cu surfaces. Step-step interaction is shown to be repulsive and consis tent with elasticity theory. Our calculations predict a lower activati on energy for diffusion of a vacancy than of an adatom for all three C u surfaces.