Bonding Changes in Compressed Superhard Graphite
Compressed under ambient temperature, graphite undergoes a transition at ~17 gigapascals. The near K-edge spectroscopy of carbon using synchrotron x-ray inelastic scattering reveals that half of the π-bonds between graphite layers convert to σ-bonds, whereas the other half remain as π-bonds in the h...
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Published in | Science (American Association for the Advancement of Science) Vol. 302; no. 5644; pp. 425 - 427 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Association for the Advancement of Science
17.10.2003
The American Association for the Advancement of Science |
Subjects | |
Online Access | Get full text |
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Summary: | Compressed under ambient temperature, graphite undergoes a transition at ~17 gigapascals. The near K-edge spectroscopy of carbon using synchrotron x-ray inelastic scattering reveals that half of the π-bonds between graphite layers convert to σ-bonds, whereas the other half remain as π-bonds in the high-pressure form. The x-ray diffraction pattern of the high-pressure form is consistent with a distorted graphite structure in which bridging carbon atoms between graphite layers pair and form σ-bonds, whereas the nonbridging carbon atoms remain unpaired with π-bonds. The high-pressure form is superhard, capable of indenting cubic-diamond single crystals. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 |
ISSN: | 0036-8075 1095-9203 |
DOI: | 10.1126/science.1089713 |