Metal Adsorption and Nucleation on Free-Standing Graphene by Low-Energy Electron Point Source Microscopy
| Autor: | Conrad Escher, Tatiana Latychevskaia, Marianna Lorenzo, Hans-Werner Fink |
|---|---|
| Přispěvatelé: | University of Zurich, Lorenzo, Marianna |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
3104 Condensed Matter Physics 530 Physics Intercalation (chemistry) Nucleation 2210 Mechanical Engineering chemistry.chemical_element 1600 General Chemistry Bioengineering 02 engineering and technology 10192 Physics Institute 01 natural sciences Atomic units law.invention Adsorption law 0103 physical sciences General Materials Science 010306 general physics 1502 Bioengineering Graphene Mechanical Engineering General Chemistry 021001 nanoscience & nanotechnology Alkali metal Condensed Matter Physics 2500 General Materials Science chemistry Chemical physics 0210 nano-technology Bilayer graphene Carbon |
| Zdroj: | Nano letters. 18(6) |
| ISSN: | 1530-6992 |
| Popis: | The interaction of metals with carbon materials (and specifically with graphene) is of importance for various technological applications. In particular, the intercalation of alkali metals is believed to provide a means for tuning the electronic properties of graphene for device applications. While the macroscopic effects of such intercalation events can readily be studied, following the related processes at an atomic scale in detail and under well-defined experimental conditions constitutes a challenge. Here, we investigate in situ the adsorption and nucleation of the alkali metals K, Cs, and Li on free-standing graphene by means of low-energy electron point source microscopy. We find that alkali metals readily intercalate between the layers of bilayer graphene. In fact, the equilibrium distribution of K and Cs favors a much-higher particle density between the layers than on the single-layer graphene. We obtain a quantitative value for the difference of the free energy of the binding between these two domains. Our study is completed with a control experiment introducing Pd as a representative of the nonalkali metals. Now, we observe cluster formation in equal measure on both single-layer and bilayer graphene; however, there was no intercalation. Our investigations thus constitute the first in situ study of metal-atom sorption of different specificity on free-standing graphene. |
| Databáze: | OpenAIRE |
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