Self-diffusion on low-index metallic surfaces: Ag and Au (100) and (111)

摘要: Using molecular-dynamics simulations and the embedded-atom method, we study homodiffusion of single adatoms on flat Ag Au (100) (111) surfaces. Our results for surfaces indicate that when thermal energies atoms become larger than energy barriers, diffusion can no longer be represented by a simple random walk since correlations between successive jumps important. We present model takes into account these correlated reproduces molecular dynamics data very well. also demonstrate knowledge barriers is not sufficient to determine preferred mechanism surface, prefactors various mechanisms vary significantly from value usually assumed. The ability transition-state theory describe tested. find, in cases considered here, static barrier equivalent dynamical activation prefactor well described as long relaxation substrate remains small. \textcopyright{} 1996 American Physical Society.