TUNNELING SPECTROSCOPY OF NANOMETER-SIZE CLUSTERS DEPOSITED ON GRAPHITE

The electronic structures of Sb, Ni, and Au clusters of nanometer size are discussed. Clusters were deposited on a graphite substrate and an alyzed with a scanning tunneling microscope in an ultrahigh-vacuum sys tem. Scanning at constant-current mode at different bias voltages was used as a method of spectroscopic measurements. Disappearing of the cl usters images at certain range of voltage biases is attributed to occu rrence of the energy gap in electronic structure of clusters, suggesti ng their nonmetallic behavior.