Non-SI utzrf.\ et?iplo~w/: Torr z 133 Pa, eV 2 1.60 x 10 l 9 J.

We have investigated the growth of three-dimensional Ag particles at atomic steps on the surface of highly oriented pyrolytic graphite using a scanning electron microscope. By controlling the growth parameters the cluster growth was confined to the steps avoiding terrace nucleation. In this way quasi-one-dimensional chains of Ag nanoclusters of approximately 10 nm diam were produced. The results suggest the viability of an important new route to the creation of controlled nanoscale structures. A comprehensive surface study indicates that cluster mobility and coalescence play an important role in the growth mechanism on the steps. Evidence was also found that the graphite surface has several different types of surface steps. A quantitative analysis of the cluster distribution on the steps was performed, to investigate the nucleation and growth processes at temperatures from 50 to 205 °C.

Nanotechnology is the application of science on the nanometre scale. It is a generic technology, with potential applications in a wide range of sectors, from electronics and computing to sensors and catalysis. In this article we ask the question, 'does gold have a role in the nanoscale world?' We have investigated the growth of three dimensional gold nanoclusters on a graphite substrate by means of scanning tunnelling microscopy (STM). The first stages of the growth of nanoscale gold wires have been demonstrated, via the nucleation of gold clusters along steps of the surface. We also show that small clusters which are approximately 1-3nm in diameter are grown on the flat terraces, and demonstrate the movement of larger clusters across the surface with the STM tip. Prospects for the application of these nanoscale building blocks are discussed.