Enhancement in Electron Field Emission of Microcrystalline Diamond Films upon Iron Coating and Annealing Processes
Autor: | I-Nan Lin, Wen-Ching Shih, Pin-Chang Huang, Huang-Chin Chen |
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Rok vydání: | 2011 |
Předmět: |
Materials science
Physics and Astronomy (miscellaneous) Annealing (metallurgy) Scanning electron microscope Material properties of diamond General Engineering General Physics and Astronomy Diamond Nanotechnology engineering.material Field electron emission Microcrystalline Chemical engineering Amorphous carbon Transmission electron microscopy engineering |
Zdroj: | Japanese Journal of Applied Physics. 50:08KE04 |
ISSN: | 1347-4065 0021-4922 |
Popis: | The electron field emission (EFE) properties of diamond films were markedly improved by Fe-coating and postannealing processes. Transmission electron microscopy examination indicated that the possible mechanism of enhancing the EFE behavior is the reaction of the Fe layer with diamond and the reprecipitation of the dissolved carbon species to form nanographite. Scanning electron micrographs showed that the Fe coating first formed Fe particles at 700 °C and then reacted with diamond, forming iron carbide (Fe3C) at 800 °C. The dissolution and reprecipitation processes occurred simultaneously during the postannealing process at higher temperatures (800–950 °C), which leads to the formation of amorphous carbon when the postannealing temperature is low (800–850 °C) and to that of nanographite when the postannealing temperature is high (900–950 °C). The 900 °C-postannealed diamond films exhibit the best EFE properties, which can be turned on at a field of E 0=2.8 V/µm, and attain an EFE current density of J e=21.4 µA/cm2 at 8 V/µm. |
Databáze: | OpenAIRE |
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