Diffusion processes relevant to the epitaxial growth of Ag on Ag(110)

By means of quenched molecular dynamics, we have studied the elementary diffusion processes (intralayer and interlayer diffusion) relevant for the epitaxial growth of Ag on Ag(110). Silver has been modeled by many-body potentials derived in the framework of the second-moment approximation to the tight-binding model. Energy barriers for diffusion on the flat surface are found strongly anisotropic. The proximity to steps alters these barriers considerably. The adatom descent from islands takes place by different mechanisms depending on the orientation and some of those mechanisms depend strongly on the island size and shape. In particular, the adatom descent at kinks is much easier on small islands than on large ones. This fact may have a strong influence on the growth character at low temperatures. Finally, the energetics of small adatom clusters is presented.