The work is aimed at characterizing structural defects on crystal surfaces and investigating their role in atom transport processes. The mechanisms by which atoms move on surfaces to produce morphology changes and surface phase transitions will be studied. A major part of the work will involve the study of atomic steps on single crystal surfaces; it will be concerned with atomic structure in the vicinity of steps, kink distributions along individual steps, interactions of pairs and groups of steps, the dynamics of step motion during mass transport processes and the correlation of nucleation sites for phase transitions with step edges. The major experimental methods for the structural and kinetic studies will be scanning tunneling microscopy, low energy electron diffraction, and surface x-ray diffraction. Experiments will be performed both on semiconductors and on metal single crystals.
