Production and Analysis of Clusters and Nanoparticles

Laser desorption mass spectrometry was used in the production and analysis of gas phase metal sulfur clusters. Clusters of gas phase aluminum, gallium, and indium sulfur were produced and analyzed using a time-of-flight mass spectrometer. Also, carbon nano-onions produced by an arc between graphite electrodes in water and the annealing of nanodiamonds were analyzed. The sulfur experiments were done by mixing metal powders with sulfur and vaporizing the mixture with a laser. The mass spectra reveal that certain gas phase clusters are stable when they satisfy electron counting rules. This gas phase correspondence in stability to condensed phase studies suggests that well-developed structure and bonding ideas can be applicable for understanding the stability and structure of gas phase clusters. Furthermore, we measured the first known mass spectrum of carbon nano-onions. Production methods and “peeling” reactions with these species are compared based on the mass of the nano-onions. INDEX WORDS: Laser vaporization, Laser desorption, Gas phase synthesis, Nanoparticles, Metal sulfur clusters, Carbon onions PRODUCTION AND ANALYSIS OF CLUSTERS AND NANOPARTICLES