Germanium clusters: More magic numbers

[摘要] Clusters of silicon and germanium exhibit multiple isomers that can be annealed to single unique structural forms. The ;;magic number;; reactivity trend observed for positive silicon clusters in the size range from 10 to 45 has also been observed in reactions with ammonia, and has also been observed with ethylene, water and trimethylamine (TMA). It was observed that Si$sb{21sp+}$ anneals to a reactive form, so is no longer a ;;magic number;;. Negative silicon ions also display the same pattern. Additionally, mass-selected germanium clusters were levitated in the FT-ICR, and probed in chemisorption reactions with nitric oxide, TMA, and water. Clusters in the 10-51 atom size range were effectively annealed to unique structural forms by collisional excitation and cooling through infrared radiation and collisions with argon. For clusters over 33 atoms in size the reactivity pattern for the two elements is the same, suggesting the structures of these clusters is identical and common to tetravalently bonded clusters. Fragmentation studies were also performed to elucidate the difference in relative stability of the clusters and a correlation between stability and reactivity was found.

[发布机构] Rice University

[效力级别] matter