Determination of atomic potential energy around step corner sites of the Ir(111) surface

The potential energy of an atom at and around the corner site of an island controls the shape of compact islands and the behavior in dendritic growth, thus it is one of the most important parameters in understanding thin film epitaxy. Using the field ion microscope we determine in details the potential energy of an Ir atom at and around the corner of the Ir(111) island. Based on the measured potential energies, many island shape and growth behavior can be understood at the atomic level.