Scanning Tunneling Spectroscopy on Deposited Platnium Clusters We report on investigations of platinum clusters with about five to 400 atoms that are deposited from a cluster beam on to crystalline graphite surfaces. Scanning tunneling spectroscopy in an UHV environment at liquid helium temperatures reveals the existence of distinct peaks in the conductivity of the cluster-on-surface system. For negative voltages, the peak separations scale with the inverse particle height, which hints at a quantum size effect in these metallic “quantum dots”. 402-404 475-479 475-479 Elsevier