Synergistic Effect of Fluorine and Hydrogen on Processes of Graphite and Diamond Formation from Fluorographite-Naphthalene Mixtures at High Pressures
| Autor: | Valery N. Khabashesku, V. N. Agafonov, Valery A. Davydov, A.V. Rakhmanina |
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| Rok vydání: | 2011 |
| Předmět: |
Diffraction
Materials science Hydrogen Carbonization chemistry.chemical_element Diamond Mineralogy Atmospheric temperature range engineering.material Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound General Energy Chemical engineering chemistry Fluorine engineering Graphite Physical and Theoretical Chemistry Naphthalene |
| Zdroj: | The Journal of Physical Chemistry C. 115:21000-21008 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp206904t |
| Popis: | Pressure–temperature-induced transformations of fluorographite CF1.1 and homogeneous mixtures of CF1.1 with naphthalene under static pressure of 8.0 GPa have been investigated by X-ray diffraction, scanning and transmission electron microscopies, and energy-dispersive X-ray analysis. It was found that carbonization of neat CF1.1 occurs at temperatures above 500 °C. Formation of graphite showing high grade of crystalline perfection has been observed already at ∼900 °C. The process of graphitization of carbon residue from CF1.1 is also characterized by high yield of planar graphite monocrystals of clear-cut polygonal shape. The formation of diamonds from CF1.1 at 8.0 GPa was not observed within all studied temperature range, up to 1500 °C. Thermal transformations of CF1.1 mixtures with naphthalene are distinguished by significantly reduced graphitization temperature threshold and a record low initiation temperature of diamond formation, 900 °C at 8.0 GPa, in comparison with various hydrocarbons. This can be... |
| Databáze: | OpenAIRE |
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