计算物理 ›› 2019, Vol. 36 ›› Issue (4): 491-497.DOI: 10.19596/j.cnki.1001-246x.7860

• • 上一篇    下一篇

过渡金属单硼化物TMB的第一性原理研究

秦平, 高振帮, 刘海敌, 陈英才   

  1. 上海海洋大学工程学院, 上海 201306
  • 收稿日期:2018-03-16 修回日期:2018-06-15 出版日期:2019-07-25 发布日期:2019-07-25
  • 作者简介:秦平(1991-),硕士研究生,研究方向为新型超硬材料设计,E-mail:pingqin2015@163.com
  • 基金资助:
    国家自然科学基金(51671126)及上海市科委科技基金(13JC1402900)资助项目

First-principles Study of Transition Metal Monoboride TMB

QIN Ping, GAO Zhenbang, LIU Haidi, CHEN Yingcai   

  1. College of Engineering Science and Technology, Shanghai Ocean University, Shanghai 201306, China
  • Received:2018-03-16 Revised:2018-06-15 Online:2019-07-25 Published:2019-07-25

摘要: 基于密度泛函理论平面赝势波法的第一性原理计算,研究过渡金属单硼化物TMB(以3d系列中的TiB、VB和CrB;4d系列中的ZrB、NbB和MoB;5d系列中的HfB、TaB和WB为例)的热力学稳定性、力学性质和微观机制.发现过渡金属单硼化物的热力学稳定与硬度异常的规律.当价电子浓度为8 e·(f.u.)-1时,热力学最稳定,且硬度最高.计算TMB的电子结构,发现TMB的价电子浓度为8 e·(f.u.)-1时,pd共价键合,有效阻碍了金属双层之间的位错滑动,防止剪切变形,致使其具有高硬度.

关键词: 过渡金属单硼化物TMB, 第一性原理, 硬度异常, 微观机制

Abstract: We study thermodynamic stability, mechanical properties, and microscopic mechanisms of transition metal monoboride TMB (take TiB, VB and CrB in 3d series; ZrB, NbB and MoB in 4d series; HfB, TaB and WB in 5d series as examples) by first-principles calculations based on density functional theory and plane pseudopotential wave method. We found thermodynamic stability and hardness anomalies of transition metal monoborides. In particular, as valence electron concentration is 8 e·(f.u.)-1, thermodynamic stability is the most stable and hardness is the highest. To reveal its mechanism, we calculated electronic structure of TMB. As valence electron concentration of TMB is at 8 e·(f.u.)-1, covalent bonding of pd blocked effectively dislocation slipping between metal bilayers, prevented shear deformation, and resulted in high hardness. These discoveries may help new superhard material designs.

Key words: transition metal monoboride TMB, first-principles, hardness anomaly, microscopic mechanism

中图分类号: