WnSm-Clusters: Possible Building Blocks for New Nanomaterials?

Since bulk WS2 forms layered structures similar to bulk graphite, this material might also built up stable cage-like fullerene structures. Large graphite-like structures (multiwall fullerenes, nanotubes) have been found in TEM experiments, but so far no anorganic fullerenes have been detected in the size regime of C60. Thus, we started a search for WS2 fullerenes by combining gas phase and deposition experiments. In the gas phase, we identified a variety of different structures (nanowires, nanoplatelets) in the size regime up to 30 metal atoms [1-3]. To investigate the suitability as building blocks, in a first attempt small size-selected WnSm-clusters were soft-landed on Ag- and Si substrates at ultrahigh vacuum conditions. These samples were analysed via HREELS and XPS. The HREELS spectra are different for the different cluster sizes indicating that these clusters survived the soft landing on the substrate and do not coalesce to bulk-like structures.
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[2] N. Bertram, Y.D. Kim, G. Ganteför, Q. Sun, P. Jena, J. Tamuliene, and G. Seifert, Chem. Phys. Lett. 396, 341 (2004)
[3] N. Bertram, J. Cordes, Y.D. Kim, G. Ganteför, S. Gemming, and G. Seifert, Chem. Phys. Lett. 418, 36 (2006)