Covalent three-dimensional carbon nanotube and derived B-C-N polymorphs with superhardness and zero Poisson's ratio

Shuang Chen; Meng Hu; Lingyu Liu; Yilong Pan; Penghui Li; Julong He; Jianning Ding

doi:10.1016/j.isci.2022.105563

Covalent three-dimensional carbon nanotube and derived B-C-N polymorphs with superhardness and zero Poisson's ratio

iScience. 2022 Nov 13;25(12):105563. doi: 10.1016/j.isci.2022.105563. eCollection 2022 Dec 22.

Authors

Shuang Chen¹, Meng Hu^{1

2}, Lingyu Liu³, Yilong Pan⁴, Penghui Li², Julong He², Jianning Ding^{1

5}

Affiliations

¹ Institute of Intelligent Flexible Mechatronics, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China.
² State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China.
³ School of Materials Science and Engineering, Xihua University, Chengdu 610 039, China.
⁴ Institute of High Pressure Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
⁵ School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China.

Abstract

Carbon is one of the most versatile atoms and fosters a wealth of carbon allotropes with superior mechanical and electronic properties. A three-dimensional covalent carbon nanotube, named CCN, with a hexagonal honeycomb-like crystalline structure is proposed theoretically. CCN consists of sp ³ bonded coaxially teamed (6,0) carbon nanotubes, and the tube walls possess intrinsic wrinkles, which trigger miraculous physical properties. The mechanical and thermal dynamic stabilities are confirmed, and molecular dynamics simulations indicate high temperature thermal stability up to 1500 K. CCN has an unusual cork-like zero Poisson's ratio along the axial direction of the nanotubes, and the axial/radial stretching or compression rarely effects the radial/axial dimensions of the nanotubes. CCN is superhard with Vickers hardness of 82.8 GPa, matching that of cubic boron nitride. Substitution B and N atoms for C atoms result in superhard CCN-B₁₂N₈ and CCN-C₈N₁₂ with quasi-zero Poisson's radio along both axial and radial directions.

Keywords: Organic chemistry; materials science; mechanical processing.