SITES, MOBILITIES, AND CLUSTER FORMATION OF IN ATOMS ON A STEPPED CU(100) SURFACE

The surface sites in In atoms deposited to a coverage of 0.013 monolayer onto a stepped Cu(100) surface were determined with low-energy ion scattering. This was done for various deposition temperatures in the range 63-300 K. The mobilities of In atoms on the terraces and along steps were deduced from the deposition-temperature dependence of the fractions of In atoms occupying different sites. It was found that, with increasing temperature, In adatoms first migrate to step edges to form one- and two-dimensional clusters and then are incorporated into the terraces at near-substitutional sites.