计算物理 ›› 2018, Vol. 35 ›› Issue (5): 613-618.DOI: 10.19596/j.cnki.1001-246x.7718

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新型石墨插层化合物HfC2结构与性质的第一性原理研究

谭俊华, 彭军辉   

  1. 太原工业学院材料工程系, 太原 030008
  • 收稿日期:2017-06-28 修回日期:2017-08-15 出版日期:2018-09-25 发布日期:2018-09-25
  • 作者简介:谭俊华(1982-),女,山西太原,硕士,讲师,主要从事第一性原理模拟研究,E-mail:Junhua_tan@163.com
  • 基金资助:
    山西省材料科学与工程重点扶持学科基金资助项目

First-Principles Study on Structure and Properties of Graphite Intercalation Compound HfC2

TAN Junhua, PENG Junhui   

  1. Department of Materials Engineering, Taiyuan Institute of Technology, Taiyuan 030008, China
  • Received:2017-06-28 Revised:2017-08-15 Online:2018-09-25 Published:2018-09-25

摘要: 在高压下,预测一种新型石墨插层化合物HfC2.采用第一性原理方法对其在0 GPa下的结构和性质进行研究,分别采用GGA-PBESOL、GGA-PW91和LDA方法进行结构优化,得到的晶体学数据基本相同.弹性常数和声子谱计算证实其力学和晶格动力学稳定性,表明HfC2在0 GPa下能够稳定存在.采用GGA-PBESOL方法计算得到HfC2的体模量和剪切模量达到265 GPa和118 GPa,Pugh比k<0.57,是一种具有高体模量的韧性材料.HfC2存在C-C、Hf-C共价作用,且具有金属特性和特殊层状结构,是其具有高体模量和韧性的原因.最后,对HfC2在0~500 GPa内的键长、体模量、剪切模量、k值等进行研究,探索其力学性质随压力变化的规律.

关键词: HfC2, 力学性质, 稳定性, 第一性原理

Abstract: At high pressures, a new graphite intercalation compound (GIC) HfC2 was predicted. We calculate structure and properties of HfC2 at 0 GPa using first-principles method. Lattice parameters of HfC2 with geometrical optimization based on GGA-PBESOL, GGA-PW91 and LDA are almost the same. With phonon dispersion curve and elastic constant, dynamical and mechanical stability of structure were verified, respectively, which meant that HfC2 could exist stability at 0 GPa. Calculated bulk modulus and shear modulus of HfC2 are 265 GPa and 118 GPa, respectively, and Pugh ratio k<0.57. With analysis of electron density and density of states, Hf-C and C-C bond showed covalent, metallically. That is reason why it has high bulk modulus and ductility. At last, we calculated bond length, bulk modulus, shear modulus and Pugh ratios of HfC2 in pressures ranging from 0 GPa to 500 GPa.

Key words: HfC2, mechanical property, stability, first-principles

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