ISSN:
1434-6079
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract. (C60) m Na n clusters are produced in a tandem laser vaporization source and analyzed by photoionization and photofragmentation time-of-flight mass spectroscopy. At low sodium coverage, the special behavior of (C60) m=1,2Na n clusters $(n\leq 6m)$ is consistent with a significant electron transfer from the first six adsorbed atoms towards each of the C60 fullerenes and an ionic-like bonding in this size range. However, the stability of the (C60)Na3 + cation is found much more pronounced than the one of (C60)Na7 + predicted to be a magic size under the hypothesis of a full charge transfer from the metal atoms to the C60 molecule. When more sodium atoms are present, metal-metal bonds tend to become preponderant and control the cluster properties. Relative to the number of sodium atoms, an odd-even alternation in their stability is explained by the high dissociation rates for even-numbered clusters. The even clusters evaporate neutral sodium atoms whereas odd ones prefer to evaporate Na2 molecules. The hypotheses for the growth of a sodium droplet that does not wet the fullerene surface or for the formation of a concentric metallic layer are discussed in the light of this study.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1140/epjd/e2003-00216-4
