Diffusive atom transport along step edges on Ag(1 1 1) at 295 K

The entropy-driven relaxation of a unique, non-equilibrium step edge configuration on the Ag(1 1 1) 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(1 1 1) is dominated by step edge diffusion at 295 K, and allow an estimate of the corresponding effective energy barrier. We obtain Eeff=0.49±0.05 eV and compare this value with recent results on island diffusion studies.