Microstructure of Quasi-Graphitic Carbons
| Autor: | W. M. Hess, L. L. Ban |
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| Rok vydání: | 1968 |
| Předmět: | |
| Zdroj: | Proceedings, annual meeting, Electron Microscopy Society of America. 26:256-257 |
| ISSN: | 2690-1315 0424-8201 |
| DOI: | 10.1017/s0424820100101025 |
| Popis: | There are many types of carbon which have the same hexagonal atomic configuration as the layer planes of graphite. These include colloidal carbon blacks and the various cokes, chars and pyrolized fibers that are used commercially. The evaporated carbon films that are utilized in electron microscopy also fit into the same category. Where all these carbons differ from graphite is in their rotational disorder about the c-axis, larger c-spacing (e.g. about 3.5-3.8 Å as compared to 3.35 Å for graphite) and smaller crystallite size.The recent work of Heidenreich, Hess and Ban has demonstrated phase contrast imaging of the graphite lattice in heat treated carbon blacks using axial illumination. The c-spacing of 3.4 Å and numerous other aspects of microstructure were resolved in an ISAF carbon black heated at 2600-3000°C. This type of carbon has been proposed as a high resolution test specimen and as a means of calibrating magnification at high electron optical magnifications. |
| Databáze: | OpenAIRE |
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