Nucleation and growth of Pd clusters on (001) SrTiO3:: Determination of diffusion and adsorption energies from cluster densities -: art. no. 094908

The nucleation and the growth of Pd on (001) SrTiO3 surfaces were studied by scanning tunneling microscopy. Between 500 and 700 degrees C the Pd nucleated as three-dimensional clusters on the (001) SrTiO3 surface. The condensation regime for the nucleation of Pd clusters on SrTiO3 could be confined by Auger electron spectroscopy and transmission electron microscopy investigations. An approximation of Venables's nucleation rate theory [J. A. Venables, Philos. Mag. 27, 697 (1973)] was used which holds for the initially incomplete and complete regimes of condensation. With this approximation, we could simultaneously extract the activation energies for the diffusion and adsorption, E-d and E-a, of Pd atoms on the (001) surface of SrTiO3. The results are compared with other metal-oxide systems, and some general trends of the nucleation behavior of metal clusters on oxide surfaces are discussed. (c) 2005 American Institute of Physics.