A new carbon allotrope with orthorhombic symmetry formed via graphitic sheet buckling

被引：11

作者：

Li, Zhen-Zhen ^{[1
,2
]}

Wang, Jian-Tao ^{[1
,2
]}

机构：

[1] Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Inst Phys, Beijing 100190, Peoples R China

[2] Univ Chinese Acad Sci, Sch Phys, Beijing 100049, Peoples R China

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2018年 / 20卷 / 35期

基金：

中国国家自然科学基金;

关键词：

X-RAY-DIFFRACTION; HIGH-PRESSURE; HEXAGONAL DIAMOND; TRANSPARENT PHASE; CRYSTAL-STRUCTURE; ROOM-TEMPERATURE; N-DIAMOND; TRANSFORMATION; COMPRESSION; STATE;

D O I：

10.1039/c8cp04129f

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We identified by ab initio calculations a new simple orthorhombic carbon allotrope with Pmc2(1) (C-2v(2)) symmetry that has a 32-atom unit cell in all-sp(3) hybridized covalent bonds. This new carbon phase can be formed from graphite via a one-layer by three-layer slip and buckling mechanism along the [210] direction above 7.16 GPa and is more favorable than previously proposed cold-compressed graphite phases such as Z-carbon and M-carbon in terms of both kinetics and energetics. Its dynamic stability has been confirmed by phonon mode analysis. Electronic band structure calculations reveal that it has a large indirect band gap of 5.91 eV, wider than that of diamond, which is expected to be optically transparent. The calculated hardness of 95.1 GPa is comparable to 97.5 GPa for diamond. These results offer insights into understanding the complex structural landscape of compressed graphite.

引用

页码：22762 / 22767

页数：6