摘要
目的设计具有超硬结构的硼铪化合物并研究其结构的稳定性、力学性质及电子性质。方法结合基于粒子群优化算法的晶体预测技术和基于密度泛函的第一性原理计算方法对Hf_(2)B_(5)晶体进行结构预测和物性计算。结果预测了一种六方相P6/m-Hf_(2)B_(5)结构,形成焓、声子谱、弹性常数计算结果表明该结构是热力学、动力学及力学稳定的,高的弹性常数和体弹模量以及小的泊松比说明这种结构具备超抗压缩性,电子态密度分析表明此结构中均存在强的B-B和Hf-B共价键。结论计算表明P6/m-Hf_(2)B_(5)的理论硬度高达37.6 GPa,是一种潜在的高硬度硬质材料。
Purposes—To design the structure of the hafnium borides with superhard character and study its structural stability,mechanical and electronic properties.Methods—Crystal structure prediction(CSP)based on the particle swarm optimization and the first-principles calculations based on density functional theory(DFT)are used to investigate the structure and properties of Hf_(2)B_(5) crystal.Results—A hexagonal P6/m-Hf_(2)B_(5) structure is predicted.The thermodynamic,dynamic,mechanical stabilities of P6/m-Hf_(2)B_(5) are confirmed by the formation enthalpies,phonon dispersion,and elastic constants.The larger values of elastic constants and bulk modulus as well as lower Poisson's ratio reveal its high incompressibility.The results of the DOS imply that there are strong B-B and Hf-B covalent bonds in Hf_(2)B_(5) crystal.Conclusions—Considerable hardness(37.6 GPa)of the P6/m-Hf_(2)B_(5) suggests that it is a potential hard material.
作者
任洋
赵亚儒
REN Yang;ZHAO Ya-ru(Institute of Physics and Optoelectronics Technology, Baoji University of Arts and Sciences, Baoji 721016, Shaanxi, China)
出处
《宝鸡文理学院学报（自然科学版）》
CAS
2022年第2期60-64,75,共6页
Journal of Baoji University of Arts and Sciences(Natural Science Edition)
基金
国家自然科学基金项目(11404008)
陕西省大学生创新创业训练计划项目(S202010721061)
宝鸡文理学院校级大学生创新创业训练计划项目(2020XJ061)。
