AU CLUSTERS DEPOSITED ON SI(III) AND GRAPHITE SURFACES

The shape, size and electronic properties of Au clusters deposited ont o Si(111) and graphite substrates are analyzed by scanning tunneling m icroscopy (STM) in ultrahigh vacuum. Deposits are sputtered from our A u STM tip by applying a sequence of voltage pulses between the tip and the substrate. Their shapes are dome type with well-controlled diamet er in the nanometer scale. This technique enables us to generate array s of Au clusters with desired periodicity and size. Such structures ar e stable and observable many days after deposition. Our results provid e a practical example that one can create nanometer-scale structures b y STM. The electronic structure of Au deposits is investigated by mean s of scanning tunneling spectroscopy. The I-V characteristics and CITS measurements reveal peculiar properties because of reduced cluster di mensions.