通讯：从石墨到金刚石：相变的反应途径。

Communication: From graphite to diamond: reaction pathways of the phase transition.

机构信息

Department of Chemistry and Biochemistry and the Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, Texas 78712-0165, USA.

出版信息

J Chem Phys. 2012 Sep 14;137(10):101101. doi: 10.1063/1.4752249.

DOI:10.1063/1.4752249

PMID:22979841

Abstract

Phase transitions between carbon allotropes are calculated using the generalized solid-state nudged elastic band method. We find a new reaction mechanism between graphite and diamond with nucleation characteristics that has a lower activation energy than the concerted mechanism. The calculated barrier from graphite to hexagonal diamond is lower than to cubic diamond, resolving a conflict between theory and experiment. Transitions are calculated to three structures of cold compressed graphite: bct C4, M, and Z-carbon, which are accessible at the experimentally relevant pressures near 17 GPa.

摘要

使用广义固态推斥弹性带方法计算了碳同素异形体之间的相变。我们发现了一种新的石墨和金刚石之间的反应机制，其成核特性具有比协同机制更低的激活能。从石墨到六方金刚石的计算势垒低于立方金刚石，解决了理论和实验之间的冲突。计算了三种冷压缩石墨结构（bct C4、M 和 Z-碳）的转变，这些结构在接近 17 GPa 的实验相关压力下是可及的。