Nucleation and growth of supported metal clusters at defect sites on oxideand halide (001) surfaces

Nucleation and growth at defect sites is discussed in terms of rate equatio n models, which can be applied to metals deposited on oxide and halide surf aces. Strong trapping and rapid adatom diffusion is characterized by an ext ensive plateau, where the island density stays constant over a wide range o f deposition parameters. Energies for defect trapping, adsorption, surface diffusion and pair binding are deduced for Pd deposited on Ar-cleaved MgO(0 0 1), which has recently been studied in situ by variable temperature atom ic force microscopy (AFM). Calculations of these energies for Pd and Ag met als on both NaCl and MgO(0 0 1) surfaces are presented, and compared with e arlier data for Ag, Au and Pd on NaCl. (C) 2000 Published by Elsevier Scien ce B.V. All rights reserved.