Unconventional features of Ag epitaxy on the Si(111)7x7 surface - art. no.045403

The population of Ag-occupied half-unit cells (HUC's) on Si(111)7x7 surface resulting from growth and annealing experiments is observed by scanning tu nneling microscopy. The temperature dependence of Ag-object density and pre ference in HUC occupation are measured. The results are interpreted with th e help of a coarse-grained kinetic Monte Carlo model. The key kinetic mecha nisms affecting Ag motion are determined, in particular transient mobility of deposited Ag atoms and the existence of a highly stable configuration of six Ae atoms in a HUC. The attempt frequency and barrier to hopping of a s ingle Ag atom between HUC's are estimated.