Phase Diagram of Quasi-Two-Dimensional Carbon, From Graphene to Diamond
Phase Diagram of Quasi-Two-Dimensional Carbon, From Graphene to Diamond
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DOI：
10.1021/nl403938g
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发表时间：
2014-02-01
期刊：
影响因子：
10.8
通讯作者：
Sorokin, Pavel B.
中科院分区：
文献类型：
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作者：
Kvashnin, Alexander G.;Chernozatonskii, Leonid A.;Sorokin, Pavel B.
我们探讨了几层石墨烯如何在减压或无压下相变成金刚石薄膜，如果该过程通过表面氢化来促进的话。这种“化学诱导相变”本质上是纳米级的现象，当表面条件直接影响热力学时，转变压力很大程度上取决于膜厚度。首次通过吉布斯自由能的从头计算，得到了准二维碳金刚石薄膜与多层石墨烯的相图（P，T，h）。它准确地描述了薄膜厚度h的作用，并显示了创造新型准二维材料的可行性。此外，还描述了石墨烯薄片的有限直径的作用和具有（110）表面的金刚石膜的可能形成。
We explore how a few-layer graphene can undergo phase transformation into thin diamond film under reduced or no pressure, if the process is facilitated by hydrogenation of the surfaces. Such a "chemically induced phase transition" is inherently nanoscale phenomenon, when the surface conditions directly affect thermodynamics, and the transition pressure depends greatly on film thickness. For the first time we obtain, by ab initio computations of the Gibbs free energy, a phase diagram (P, T, h) of quasi-two-dimensional carbon diamond film versus multilayered graphene. It describes accurately the role of film thickness h and shows the feasibility of creating novel quasi-two-dimensional materials. Further, the role of finite diameter of graphene flakes and possible formation of the diamond films with the (110) surface are described as well.