Fullerene-structured nanowires of silicon

Silicon vapor from a magnetron sputter source was deposited onto highly ori ented pyrolytic graphite, resulting in the formation of nanoscale wires. Th e structures were analyzed by scanning tunneling microscopy. The wires are from 3 to 7 nm in diameter and at least 100 nm long. They tend to be assemb led parallel in bundles. In order to understand the observed quasi-one-dime nsional structures, diamondlike and fullerenelike wire models are construct ed. Molecular-orbit calculations yield binding energies and band gaps of su ch structures, and lead us to propose a fullerene-type Si-24-based atomic c onfiguration for nanowires of silicon. [S0163-1829(99)02740-X].