Low-energy electron diffraction study of potassium adsorbed on single-crystal graphite and highly oriented pyrolytic graphite
| Autor: | Ronan McGrath, Sharon Finberg, Joseph Smerdon, Renee D. Diehl, K. Pussi, Matti Lindroos, Nicola Ferralis |
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| Jazyk: | angličtina |
| Předmět: |
Materials science
Low-energy electron diffraction Potassium chemistry.chemical_element 02 engineering and technology F500 021001 nanoscience & nanotechnology Condensed Matter Physics Alkali metal 01 natural sciences Electronic Optical and Magnetic Materials Crystallography Adsorption Electron diffraction Highly oriented pyrolytic graphite chemistry 0103 physical sciences Graphite 010306 general physics 0210 nano-technology Single crystal |
| ISSN: | 1098-0121 |
| Popis: | Potassium adsorption on graphite has been a model system for the understanding of the interaction of alkali metals with surfaces. The geometries of the $(2\ifmmode\times\else\texttimes\fi{}2)$ structure of potassium on both single-crystal graphite (SCG) and highly oriented pyrolytic graphite (HOPG) were investigated for various preparation conditions for graphite temperatures between 55 and 140 K. In all cases, the geometry was found to consist of $\mathrm{K}$ atoms in the hollow sites on top of the surface. The $\mathrm{K}$-graphite average perpendicular spacing is $2.79\ifmmode\pm\else\textpm\fi{}0.03\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$, corresponding to an average $\mathrm{C}\text{\ensuremath{-}}\mathrm{K}$ distance of $3.13\ifmmode\pm\else\textpm\fi{}0.03\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$, and the spacing between graphite planes is consistent with the bulk spacing of $3.35\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$. No evidence was observed for a sublayer of potassium. The results of dynamical LEED studies for the clean SCG and HOPG surfaces indicate that the surface structures of both are consistent with the truncated bulk structure of graphite. |
| Databáze: | OpenAIRE |
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