ATOMIC LEVEL STUDIES OF THE DYNAMICS AND DYNAMICAL BEHAVIOR OF SOLID SURFACES

Abstract

Some of our recent results on the dynamics and dynamical behavior of atoms at metal surfaces are presented. Long range charge density oscillations due to chemisorbed impurities have been observed with the FIM. Two adatoms can interact with each other through mutual perturbation of the surface. This interaction is very weak, and exhibits a small but long range oscillatory tail. Surface self diffusion of adatoms can occur at about 1/10 to 1/5 the melting point of metals. This diffusion occurs by either atomic hopping or by atomic replacement-displacement. Diffusion of ledge atoms along a lattice step can occur at a similar temperature. At about 1/5 the melting point of a metal, dissociation of step edge atoms to terraces can occur and lattice steps can also start to roughen. Energetics of the atomic processes involved can be studied from their temperature dependences of their rates of occurrence and also from the densities of surface defects created. Recent progress in theoretical calculations makes it possible to compare them directly with experimental result, thus gaining insights into the dynamics in the dynamical behavior of metal surfaces.