No abstract

No abstract

No abstract

Individual clusters of gold, grown in a gas aggregation reactor and deposited on a variety of different substrates, have been studied using a combination of scanning tunneling microscopy, field emission techniques, and field ion microscopy. The scanning tunneling microscope studies show that by proper choice of substrate, individual nanometer-sized clusters can be reproducibly imaged and studied. The field emission and field ion microscope studies yield information about the work function and melting temperature of individual supported clusters.

Controlled size clusters of Au with a diameter of 13 Å, prepared using a multiple expansion cluster source, have been supported on highly oriented pyrolytic graphite and observed with a scanning tunneling microscope. A reliable constant-current signature for a metallic cluster supported on a graphite substrate is identified. Images of the supported Au clusters are found to exhibit a narrow size distribution and a diameter which is in close agreement with the diameter predicted from conditions in the multiple expansion cluster source.