Surface Ostwald ripening of Pd nanoparticles on the MgO (100) surface

Morphological changes of Pd nanoparticles on the (100) surface of MgO singl e crystal were investigated by Auger electron spectroscopy in the temperatu re range of 873-983 K. The size and distribution of clusters were also exam ined by means of atomic force microscopy. It was shown that there was pract ically no decrease of the effective thickness of deposited Pd during heat t reatments under 6 x 10(-9) mbar. Assuming that the observed change in the A uger intensities is due to the surface Ostwald ripening the temperature dep endence of the surface mass transport diffusion coefficients can be given a s D'(s) = (1.6(-1.34)(+8.2)) x 10(-8) exp{-(136+/-15)kJ mol(-1)/RT}m(2) s(- 1). PACS: 82.80.Pv; 61.46.+w; 66.30.-h.