摘要
Boron and its compounds have attracted much attention due to their interesting and complex structures[1-4].In particular,boron-rich compounds containing icosahedral structures have excellent properties,such as low density,high hardness,high melting point and low wear coffi-cient.
富硼化合物通常为潜在的超硬材料,尽管之前的研究提出了不同晶型的BN超硬材料,但尚未发现超硬的富硼氮化物.本文采用基于粒子群优化算法的结构预测方法,结合第一性原理计算,对富硼氮化物在压力下的稳定成分及结构进行系统研究.结果表明,在B4N、B6N和B8N中,硼原子都能够形成B12二十面体.在0–20 GPa压力范围内,B6N是热力学稳定的,而B4N和B8N是亚稳的.电子性质计算表明,预测的Cmca B6N和Immm B6N为半导体,其他均为金属.声子和弹性常数计算表明,所有预测结构都具有动力学稳定性和机械稳定性.值得关注的是,B4N和B6N的维氏硬度分别为45和42 GPa,表明其为潜在的超硬材料.此研究丰富了B-N体系相图,并为实验上探索超硬材料提供了丰富的理论指导.
作者
Linyan Wang
Rongxin Sun
Wenhui Liu
Zhikang Yuan
Aitor Bergara
Xiaowei Liang
Shuai Chen
Xiang-Feng Zhou
Bo Xu
Julong He
Dongli Yu
Guoying Gao
Yongjun Tian
王林妍;孙荣鑫;刘雯慧;袁智康;Aitor Bergara;梁笑微;陈帅;周向锋;徐波;何巨龙;于栋利;高国英;田永君(Center for High Pressure Science(CHiPS),State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China;Departmento de Física de la Materia Condensada,Universidad del País Vasco,UPV/EHU,UPV/EHU,48080 Bilbao,Spain;Donostia International Physics Center(DIPC),20018 Donostia,Spain;Centro de Física de Materiales CFM,Centro Mixto CSIC-UPV/EHU,20018 Donostia,Spain)
基金
supported by the Fostering Program of Major Research Plan of the National Natural Science Foundation of China(91963115)
the National Key R&D Program of China(2018YFA0703400)
the National Natural Science Foundation of China(51732010)
the Ph D Foundation by Yanshan University(B970)
financial support from the Spanish Ministry of Economy and Competitiveness(FIS2016-76617-P)
the Department of Education,Universities,Research of the Basque Government and the University of the Basque Country(IT756-13)。