Prediction of Superhard BN_(2) with High Energy Density  

作　　者：Yiming Zhang Shuyi Lin Min Zou Meixu Liu Meiling Xu Pengfei Shen Jian Hao Yinwei Li 张逸铭;林舒怡;邹敏;刘玫序;徐美玲;申鹏飞;郝健;李印威(Laboratory of Quantum Functional Materials Design and Application,School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou 221116,China;Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen 518055,China)

机构地区：[1]Laboratory of Quantum Functional Materials Design and Application,School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou 221116,China [2]Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen 518055,China

出　　处：《Chinese Physics Letters》2021年第1期125-130,共6页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(Grant Nos.12074154,11904142 and 11722433);the Science and Technology Project of Xuzhou(Grant No.KC19010);the Six Talent Peaks Project and the 333 High-Level Talents Project of Jiangsu Province;the Natural Science Research Projects of Colleges and Universities in Jiangsu Province(Grant No.19KJB140001)。

摘　　要：Considering that pressure-induced formation of short,strong covalent bonds in light-element compounds can produce superhard materials,we employ structure searching and first-principles calculations to predict a new class of boron nitrides with a stoichiometry of BN_(2),which are stable relative to alpha-B and alpha-N_(2) at ambient pressure.At ambient pressure,the most stable phase has a layered structure(h-BN_(2)) containing hexagonal BN layers between which there are intercalated N_(2) molecules.At 25 GPa,a three-dimensional P4_(2)/mmc structure with single N-N bonds becomes the most stable.Dynamical,thermal,and mechanical stability calculations reveal that this structure can be recovered under ambient conditions.Its calculated stress-strain relations demonstrate an intrinsic superhard nature with an estimated Vickers hardness of ~43 GPa.This structure has a potentially high energy density of ~4.19 kJ/g.

关 键 词：AMBIENT STRUCTURE HEXAGONAL 

分 类 号：TQ163[化学工程—高温制品工业]