EFFECTS OF HYDROGEN IN NI(100) SUBMONOLAYER HOMOEPITAXY

The effects of hydrogen in Ni(100) submonolayer homoepitaxy have been investigated by classical-potential total-energy calculations with sem iclassical hydrogen zero-point-energy corrections. The fast diffusion of H on a flat Ni(100) surface is found to persist even when the surfa ce is decorated with various intrinsic defects such as Ni adatoms, isl ands, and steps created during epitaxial growth. On the other hand, th e presence of H significantly enhances the mobility of both Ni adatoms and Ni islands, resulting in a decrease in the Ni island density and a corresponding increase in the average island size. These results sug gest that hydrogen will function as an antisurfactant in Ni(100) homoe pitaxy. Connections to available experiments are made.