噬石墨烯：一种低能石墨烯同素异形体，由 5-6-7 元碳环组成，具有扭曲的狄拉克锥。

Phagraphene: A Low-Energy Graphene Allotrope Composed of 5-6-7 Carbon Rings with Distorted Dirac Cones.

机构信息

Peter Grünberg Research Center, Nanjing University of Posts and Telecommunications , Nanjing, Jiangsu 210003, China.

Department of Geosciences, Center for Materials by Design, and Institute for Advanced Computational Science, Stony Brook University , Stony Brook, New York 11794, United States.

出版信息

Nano Lett. 2015 Sep 9;15(9):6182-6. doi: 10.1021/acs.nanolett.5b02512. Epub 2015 Aug 17.

DOI:10.1021/acs.nanolett.5b02512

PMID:26262429

Abstract

Using systematic evolutionary structure searching we propose a new carbon allotrope, phagraphene [fæ'græfi:n], standing for penta-hexa-hepta-graphene, because the structure is composed of 5-6-7 carbon rings. This two-dimensional (2D) carbon structure is lower in energy than most of the predicted 2D carbon allotropes due to its sp(2)-binding features and density of atomic packing comparable to graphene. More interestingly, the electronic structure of phagraphene has distorted Dirac cones. The direction-dependent cones are further proved to be robust against external strain with tunable Fermi velocities.

摘要

利用系统进化结构搜索，我们提出了一种新的碳同素异形体，Phagraphene [fæ'græfi:n]，代表五倍六倍七倍石墨烯，因为该结构由 5-6-7 个碳环组成。由于其 sp(2)键合特征和与石墨烯相当的原子堆积密度，这种二维（2D）碳结构的能量低于大多数预测的 2D 碳同素异形体。更有趣的是，Phagraphene 的电子结构具有扭曲的狄拉克锥。进一步证明，与外部应变相关的各向异性锥具有可调谐费米速度的鲁棒性。