ATOMIC EVENTS AT LATTICE STEPS AND CLUSTERS - A DIRECT VIEW OF CRYSTAL-GROWTH PROCESSES

The ability of the field ion microscope to depict individual metal atoms adsorbed on metal surfaces has made it feasible to directly examine the atomic events participating in crystal growth. Of special interest are phenomena occurring at lattice steps, where atoms are incorporated into the crystal. Work to define these phenomena on the atomic level has revealed a variety of processes much larger than anticipated from classical theories of growth. Such studies are briefly surveyed, with special emphasis on the diffusion of adatoms toward steps, their subsequent incorporation, atomic motion along steps, and condensation of atoms from the vapor, both on clusters and on crystal terraces.