Diffusive atom transport along step edges on Ag(111) at 295 K

The entropy-driven relaxation of a unique, non-equilibrium step edge configuration on the Ag(111) surface was observed using time-resolved STM imaging at room temperature. Using the Gibbs-Thomson relation, the relaxation process is quantitatively described as diffusive mass transport in terms of a gradient in the chemical potential along the monoatomic step edge. The STM data directly show that mass transport on Ag(111) is dominated by step edge diffusion at 295 K, and allow an estimate of the corresponding effective energy barrier. We obtain E-eff = 0.49 +/- 0.05 eV and compare this value with recent results on island diffusion studies. (C) 2003 Elsevier B.V. All rights reserved.