Related Content
Search Google Scholar for:
More Information
Related Jobs from ScienceCareers
|
|
Science 17 October 2003:
Vol. 302. no. 5644, pp. 425 - 427
DOI: 10.1126/science.1089713
|
|
Reports
Bonding Changes in Compressed Superhard Graphite
Wendy L. Mao,1,4*
Ho-kwang Mao,1,4
Peter J. Eng,2,3
Thomas P. Trainor,2,7
Matthew Newville,2
Chi-chang Kao,5
Dion L. Heinz,1,3
Jinfu Shu,4
Yue Meng,6
Russell J. Hemley4
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  -bonds between graphite layers convert to  -bonds, whereas the other half remain as -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 -bonds, whereas the nonbridging carbon atoms remain unpaired with -bonds. The high-pressure form is superhard, capable of indenting cubic-diamond single crystals.
1 Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637, USA.
2 Consortium for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637, USA.
3 James Franck Institute, University of Chicago, Chicago, IL 60637, USA.
4 Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
5 National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973, USA.
6 High Pressure Collaborative Access Team, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
7 Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, AK 99775, USA.
* To whom correspondence should be addressed. E-mail: wmao{at}chicago.edu
Read the Full Text
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
- X-ray Raman scattering study of MgSiO3 glass at high pressure: Implication for triclustered MgSiO3 melt in Earth's mantle.
- S. K. Lee, J.-F. Lin, Y. Q. Cai, N. Hiraoka, P. J. Eng, T. Okuchi, H.-k. Mao, Y. Meng, M. Y. Hu, P. Chow, et al. (2008)
PNAS
105, 7925-7929
| Abstract »
| Full Text »
| PDF »
- X-ray-induced dissociation of H2O and formation of an O2-H2 alloy at high pressure..
- W. L. Mao, H.-k. Mao, Y. Meng, P. J. Eng, M. Y. Hu, P. Chow, Y. Q. Cai, J. Shu, and R. J. Hemley (2006)
Science
314, 636-638
| Abstract »
| Full Text »
| PDF »
- A quenchable superhard carbon phase synthesized by cold compression of carbon nanotubes.
- Z. Wang, Y. Zhao, K. Tait, X. Liao, D. Schiferl, C. Zha, R. T. Downs, J. Qian, Y. Zhu, and T. Shen (2004)
PNAS
101, 13699-13702
| Abstract »
| Full Text »
| PDF »
|
|
