کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1592649 | 1002668 | 2012 | 4 صفحه PDF | دانلود رایگان |

Two new carbon allotropes (H-carbon and S-carbon) are proposed, as possible candidates for the intermediate superhard phases between graphite and diamond obtained in the process of cold compressing graphite, based on the results of first-principles calculations. Both H-carbon and S-carbon are more stable than previously proposed M-carbon and W-carbon and their bulk modulus are comparable to that of diamond. H-carbon is an indirect-band-gap semiconductor with a gap of 4.459 eV and S-carbon is a direct-band-gap semiconductor with a gap of 4.343 eV. The transition pressure from cold compressing graphite is 10.08 GPa and 5.93 GPa for H-carbon and S-carbon, respectively, which is in consistent with the recent experimental report.
► Two new carbon phases are proposed with remarkable stability.
► They can be obtained by cold compressing AB-stacking graphite.
► They are transparent superhard materials comparable to diamond.
► Our discussion is significant for understanding phase transition in graphite.
Journal: Solid State Communications - Volume 152, Issue 16, August 2012, Pages 1560–1563