SILICON-CARBON MIXED CLUSTERS

Binary clusters SinCm are produced in a laser vaporization source from SixC1-x mixed targets. Different composition regimes are investigated by abundance and photoinduced dissociation mass spectroscopy. In the case of stoichiometric silicon-carbide clusters (x = 0.5), no clear ma gic size is detected but rather the marked effects of a lower binding energy of silicon as compared to carbon atoms. The structural changes induced by the presence of foreign atoms are discussed in the case of carbon-rich clusters (x << 1) for which the formation of heterofullere nes is observed. (C) 1997 Elsevier Science B.V.