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论文类型： 期刊论文

发表时间： 2013-05-23

发表刊物： SCIENTIFIC REPORTS

收录刊物： SCIE

卷号： 3

ISSN号： 2045-2322

摘要： Pressure-induced bond type switching and phase transformation in glassy carbon (GC) has been simulated by means of Density Functional Theory (DFT) calculations and the Stochastic Quenching method (SQ) in a wide range of pressures (0-79 GPa). Under pressure, the GC experiences a hardening transition from sp-and sp(2)-type to sp(3)-type bonding, in agreement with previous experimental results. Moreover, a new crystalline carbon allotrope possessing R3 symmetry (R3-carbon) is predicted using the stochastic SQ method. The results indicate that R3-carbon can be regarded as an allotrope similar to that of amorphous GC. Avery small difference in the heat of formation and the coherence of the radial and angular distribution functions of GC and the R3-carbon structure imply that small perturbations to this crystalline carbon allotrope may provide another possible amorphization pathway of carbon besides that of quenching the liquid melt or gas by ultra-fast cooling.