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A new natural,super-hard,transparent polymorph of carbon from the Popigai impact crater,Russia 总被引:1,自引:0,他引:1
Ahmed El Goresy Leonid S Dubrovinsky Philippe Gillet Smail Mostefaoui Günther Graup Michael Drakopoulos Alexandre S Simionovici Varghese Swamy Victor L Masaitis 《Comptes Rendus Geoscience》2003,335(12):889-898
A natural shockwave event led to the formation of a new crystalline polymorph of carbon in gneisses from the Popigai crater, Russia. The new species occupies the interior of a multiphase assemblage and is entirely enveloped by lonsdaleite and graphite. Polishing hardness of this new phase is greater than that of lonsdaleite. Micro-beam synchrotron X-ray diffraction, imaging and fluorescence studies revealed a pure transparent carbon phase. The diffraction pattern is indexed in terms of a cubic cell (a=14.697 Å, space group Pm3m.). This species was neither encountered in static or dynamic high-pressure experiment nor predicted by theoretical calculations. To cite this article: A. El Goresy et al., C. R. Geoscience 335 (2003). 相似文献
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