The initial stages of Ag/Ag(100) homoepitaxy: Scanning tunneling microscopy experiments and Monte Carlo simulations

Results are presented of a scanning tunneling microscopy study of Ag/Ag(100) homoepitaxy. We examine both submonolayer nucleation and growth of two-dimensional islands, for temperatures between 295 and 370 K, and the initial stages of multilayer kinetic roughening at 295 K. Comparison with results of Monte Carlo simulations for an appropriate model for metal(100) homoepitaxy produces estimates of 330 +/- 5 meV for the terrace diffusion barrier, and an effective value of 30 +/- 5 meV for the additional step-edge barrier (assuming a common prefactor of 10(12)/s). We also assess adatom-adatom bonding by analyzing the transition from irreversible to reversible island formation.