Measurement of Energies Controlling Ripening and Annealing on Metal Surfaces

The successful experimental implementation of a powerful concept for the determination of energies controlling ripening and annealing on surfaces is reported. On a Ag(111) surface, we have prepared and studied the decay of well-defined nanostructures for which an available exact theoretical description can be used. The decay is followed by fast scanning tunneling microscopy at various temperatures to determine the 2D evaporation rate of atoms from island edges and the interlayer mass transport. An activation energy for 2D evaporation of $(0.71\pm 0.03)\mathrm{eV}$ and an Ehrlich-Schwoebel barrier of $(0.13\pm 0.04)\mathrm{eV}$ are determined.