Diffusion and aggregation of adatoms on faceted Pd/Mo(111) surface

Diffusion of Pd adatoms on faceted Pd/Mo(111) surface with hill and valley structure is studied by kinetic Monte Carlo method. The surface consists of {211} channeled facets separated by concave and convex edges. It is shown that diffusion on the faceted surface is significantly reduced with comparison to diffusion on (112) surface by the presence of concave edges. A simple formula for the diffusion coefficient is proposed. The growth of linear structures, studied at low coverage θ = 0.1, depends on the cross-channel diffusion, although the cross-channel diffusion coefficient is by 6-8 orders of magnitude smaller than the in-channel diffusion coefficient. We observed that most of atomic structures grow in valleys and the average size of the structure increases with increase of facet size.

► Using kMC we simulate diffusion on faceted Pd/Mo(111) surface. ► Diffusion of adatom on hill and valley structure is suppressed due to existence of concave edges. ► Rare events are important in the growth process. ► Linear structures grow in valleys and their sizes depend on facet size.