SCANNING TUNNELING MICROSCOPY OF SINGLE PLATINUM ATOMS AND SMALL PLATINUM CLUSTERS ON HIGHLY ORIENTED PYROLYTIC-GRAPHITE

We did a topographic study of single platinum atoms, platinum dimers and trimers on highly oriented pyrolytic graphite using a scanning tunneling microscope in air. The particles were produced by evaporation of platinum onto the surface. The platinum atoms and the small clusters could be imaged on the graphite surface without changes for many scans. We show the adsorption site distribution for the monomers. The average bond length of a Pt-dimer on graphite is 2.45 angstrom. We found only two kinds of Pt-trimers, as a linear chain or as an equilateral triangle. The average bond length is 2.66 angstrom.