Superhard orthorhombic phase of B2CO compound
A lonsdaleite-like orthorhombic structure B2CO(oP8-B2CO)with strong sp3 covalent B‐C andB‐O bonds has been predicted theoretically by using the crystal structure prediction package CALYPSO.The mechanical,dynamical and thermodynamic stabilities of oP8-B2CO are verified by independent elastic constants,phonon dispersion spectrum and formation enthalpy,respectively.Pressure may promote synthesis of oP8-B2CO,which is demonstrated by calculating the relationship of formation enthalpies for oP8-B2CO via pressure.Based on bond resistance model for hardness,oP8-B2CO has a high hardness value of 47.70 GPa.Band structures calculation illustrates that all B2CO phases are semiconducting with indirect band gaps and oP8-B2CO has the widest band gap(3.540 eV)relative to tP4-B2CO(1.658 eV)and tI16-B2CO(2.988 eV).The superhardness and tunable band gap open an extensive industrial application and scientific research for B2CO compounds.
Chao Liu Zhisheng Zhao Kun Luo Meng Hu Mengdong Ma Julong He
State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China
国内会议
大连
英文
192-197
2016-09-24（万方平台首次上网日期，不代表论文的发表时间）