A metallic superhard boron carbide:first-principles calculations
A monoclinic BC3 phase(denoted M-BC3)has been predicted using first principles calculations.The M-BC3 structure is formed by alternately stacking sequences of metallic BC-layers and insulating C atom layers,thus,the structure exhibits two-dimensional conductivity.Its stability has been confirmed by our calculations of the total energy,elastic constants,and phonon frequencies.The pressure of phase transition from graphite-like BC3 to M-BC3 is calculated to be 9.3 GPa,and the theoretical Vickers hardness of M-BC3 is 43.8 GPa,this value indicates that the compound is a potentially superhard material.By comparing Raman spectral calculations of M-BC3 and previously proposed structures with the experimental data,we speculate that the experimentally synthesized BC3 crystal may simultaneously contain M-BC3 and Pmma-b phases.
Mengdong Ma Bingchao Yang Zihe Li Meng Hu Qianqian Wang Lin Cui Dongli Yu Julong He
State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,Hebei Province,China
国内会议
大连
英文
173-176
2016-09-24（万方平台首次上网日期，不代表论文的发表时间）