J. Merikoski et al., EFFECT OF KINKS AND CONCERTED DIFFUSION MECHANISMS ON MASS-TRANSPORT AND GROWTH ON STEPPED METAL-SURFACES, Surface science, 387(1-3), 1997, pp. 167-182
We study the effect of kinks and concerted atomic mechanisms on diffus
ion processes relevant to metal-on-metal homoepitaxy on fee metal surf
aces vicinal to the fee (100) direction. First, we carry out extensive
finite-temperature molecular dynamics simulations based on the effect
ive medium theory to search for diffusion mechanisms that dominate the
mass transport perpendicular and parallel to step edges. Then, the en
ergetics of these processes are studied by ground state calculations.
Our results show that kinks play an important role for diffusion both
across and along step edges. In particular, the combined effect of kin
ks and concerted exchange is found to be able to remove locally the st
ep edge barrier for mass transport across the step. The relative impor
tance of some of the processes depends on the local tilt of the interf
ace, We report results for copper, silver, and nickel, and discuss the
generic features of energetics of diffusion processes in effective me
dium theory and other semi-empirical many-atom models. We also conside
r the implications of our results on surface growth and for models of
surface growth under molecular beam epitaxy conditions. (C) 1997 Elsev
ier Science B.V.