ATOMIC STRUCTURES OF AG ON ROOT-3X-ROOT-3 AG SI(111) AND ON 7X7 SI(111)/

Time evolution of atomic structures during Ag deposition and in subseq uent annealing on both substrates, root 3 x root 3 Ag/Si(111) and 7 x 7 Si(111), have been studied with use of the lattice gas model. The in terrelation between the calculated atomic structures and the observed surface conductance is investigated. On root 3 x root 3 Ag/Si(111), Ag grows in an island mode and Ag adatoms coexist with 3-dimensional Ag islands. It was found that the time dependence of adatom density shows peculiar behavior and is strongly correlated to the observed variatio n of tile surface conductance. On 7 x 7 Si(111) substrate, Ag grows in a layer mode, The observed variation of surface conductance indicates that the conductance from 3 lower overlayers is suppressed.