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人工晶体学报 ›› 2021, Vol. 50 ›› Issue (12): 2255-2261.

• 研究论文 • 上一篇    下一篇

高压下ReB2的结构特性及弹性性质

张立宏, 雷慧茹   

  1. 山西工程技术学院基础教学部,阳泉 045000
  • 收稿日期:2021-08-16 出版日期:2021-12-15 发布日期:2022-01-06
  • 通讯作者: 雷慧茹,讲师。E-mail:leihuiru1988@163.com
  • 作者简介:张立宏(1987—),男,山西省人,讲师。E-mail:207274060@163.com
  • 基金资助:
    山西工程技术学院校级科研项目(2021001)

Structural Characteristic and Elastic Property of ReB2 under High Pressure

ZHANG Lihong, LEI Huiru   

  1. Department of Basic Subjects Teaching, Shanxi Institute of Technology, Yangquan 045000, China
  • Received:2021-08-16 Online:2021-12-15 Published:2022-01-06

摘要: 本文采用密度泛函理论中的赝势平面波法计算了ReB2P63/mmc晶体结构(即hP6-ReB2)的结构特性及弹性性质。在计算了hP6-ReB2的平衡结构参数后,从热力学、动力学及机械力学三方面验证了其结构稳定性。研究发现,hP6-ReB2在高压下的弹性系数、各个弹性模量均随压强的增加而增大。泊松比显示hP6-ReB2表现为脆性。三种类型的弹性波随压强的变化趋势显示hP6-ReB2为弹性各向异性晶体。经估算,hP6-ReB2结构的维氏硬度约为38.2 GPa。电子态密度揭示了hP6-ReB2的Re—B和B—B之间存在着强共价键,并且随着压强的增加共价键逐渐增强。

关键词: 高硬度材料, ReB2, 高压, 结构特性, 弹性性质, 硬度, 态密度

Abstract: The structural characteristic and elastic property of ReB2 in P63/mmc structure (hP6-ReB2) were computed using the pseudopotential plane-wave methods based on the density functional theory. The equilibrium structural parameters of hP6-ReB2 were calculated and its stability was verified thermodynamically, dynamically, and mechanically. It is found that the elastic constants, aggregate moduli increase as the pressure increases, and the Poisson ratio σ of hP6-ReB2structure shows its brittleness, and the elastic waves reveals its elastic anisotropy. In addition, the obtained Vickers hardness of hP6-ReB2 is 38.2 GPa. The density of electronic states reveals that there is a strong covalent bond between Re-B and B-B of hP6-ReB2, and the covalent bond increases gradually with the increase of pressure.

Key words: high hardness material, ReB2, high pressure, structural characteristic, elastic property, hardness, density of state

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