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O: Fachverband Oberflächenphysik
O 69: Nanostructures at Surfaces: Dots, Particles, Clusters
O 69.8: Poster
Mittwoch, 9. März 2016, 18:15–20:30, Poster A
High-Temperature CsxC58 Solids — •Weippert Jürgen1, Ulas Seyithan1, Kern Bastian1, Malik Sharali2, Amati Matteo3, Gregoratti Luca3, Kiskinova Maya3, Strelnikov Dmitry1, Böttcher Artur1, and Kappes Manfred M.1,2 — 1Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany — 2Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany — 3ESCA microscopy beamline Elettra - Sincrotrone Trieste, ScPA Area Science Park, 34149 Basovizza-Trieste, Italy
Co-depositing Cs and C58+ on HOPG surface led to a new material, CsxC58. The C58 carbon clusters form a scaffold which gets doped by Cs via diffusion across the empty interstitial sites to form bulk CsxC58. Upon heating most of the material survives to yield a doped high-temperature non-IPR fullerene solid, HT-CsxC58. This solid remains stable up to 1100 K, a temperature at which CsxC60 no longer exists. HT-CsxC58 exhibits considerably depleted Cs content (x<2) relative to the as-prepared CsxC58 bulk. The unique thermal stability results from covalent C-C bonds connecting the carbon cages. The Cs dopants contribute to the stability via weak ionic bonds with -C58-C58- oligomers. The HT-CsxC58 material shows a higher defect density, which we attribute to Cs ions relieving the defecting of cages during heating. The topography of the HT-CsxC58 material is dominated by coexisting areas distinguished by their Cs/C58 ratio. The Cs rich islands become striking surface features after air exposure.