LASER-DRIVEN SYNTHESIS OF CARBON AND SILICON CLUSTERS FROM GAS-PHASE REACTANTS

A newly developed technique is employed for the production of carbon a nd silicon cluster beams starting from gaseous compounds. It is based on the CO2-laser-induced decomposition of molecular gases containing c arbon and silicon, such as C2H2 and SiH4, in a flow reactor. In order to decompose acetylene, SF6 is used as a sensitizer. By introducing a skimmer into the reaction zone, the generated silicon and carbon clust ers are transferred to free molecular flow and analyzed with a time-of -flight mass spectrometer. It is shown that the technique can be effic iently employed to produce fullerenes C-60 and C-70 and, in the case o f silicon, ultrapure nanosized particles of up to 3-nm diameter.