Date of Award
Doctor of Philosophy
James W. Evans
Mark S. Gordon
Theoretical studies of the nucleation and growth of metal films are performed, where the focus is the Molecular Beam Epitaxial (MBE) growth of Ag on the Ag(100) surface. Ag films grown under MBE, for the temperatures and atomic fluxes considered here (0→300K), are very far from equilibrium structures, due to the breaking of detailed balance during deposition. Included are studies of: metal film growth at very low temperatures; the temperature dependence of "mound" formation; the temperature dependence of kinetic roughening; the effect of the step-edge barrier on very thin films, and the post-deposition time dependence of nucleation. For these studies a range of lattice gas models are developed that are thought to contain the essential physics. These models contain such features as terrace diffusion, realistic edge diffusion process, a non-uniform Erlich-Schwoebel barrier, "restricted" and normal Downward Funneling, and low barrier diffusion process along micro-facets. The models were then tested by first performing a Kinetic Monte-Carlo simulation, and comparing the results to experimental data generated from previous Scanning Tunneling Microscopy studies. The models not only proved to be in good agreement with average quantities of the experimental film, but also proved to reproduce the details of the experimental morphologies quite well.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu
Kyle John Caspersen
Caspersen, Kyle John, "Theoretical studies of the nucleation and growth of thin metal films: a focus on Ag deposited on Ag(100) " (2001). Retrospective Theses and Dissertations. 630.