Scanning tunneling microscopy has shown that large, two-dimensional Ag clusters undergo observable diffusion on Ag(100). The variation of the diffusion coefficient with cluster size in the range studied, 100 to 540 atoms per cluster, indicates that two-dimensional evaporation-condensation is the main mechanism of cluster diffusion. The experimental data consistently show evidence for a backward-correlation in the cluster motion. The meaning and origin of this correlation is discussed.
Available at: http://works.bepress.com/patricia_thiel/108/