Aggregation of gold condensate on HOPG substrate

Abstract

Island growth of Au evaporated in vacuum on HOPG substrates was studied using STM. Experiments showed aggregation of 3D clusters when the HOPG substrate contains adsorbate formed after cleaving under ambient conditions. Adsorbate layer on the surface supports growth of small particles with diameters from 5 to 15 nm which aggregate, stick together and form large complex islands. The density of the aggregates is not sensitive to the deposition rate but depends rather on the presence of the adsorbate molecules (water molecules are expected to be most important due to their large dipole momentum). No significant dependence of diameter of finest clusters on deposition rate and film mass thickness was observed.