吉林大学学报(理学版)

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镧系氮化物弹性性质与光学性质的第一性原理计算

杨晓翠1, 赵衍辉1, 刘芳1, 罗香怡1, 肖俊平2   

  1. 1. 白城师范学院 物理学院, 吉林 白城 137000; 2. 吉林大学 超硬材料国家重点实验室, 长春 130012
  • 收稿日期:2013-01-31 出版日期:2013-09-26 发布日期:2013-09-17
  • 通讯作者: 杨晓翠 E-mail:yxc0622@163.com

FirstPrinciples Calculations of Elastic and Optical Properties of LnN

YANG Xiaocui1, ZHAO Yanhui1, LIU Fang1, LUO Xiangyi1, XIAO Junping2   

  1. 1. College of Physics, Baicheng Normal University, Baicheng 137000, Jilin Province, China;2. State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
  • Received:2013-01-31 Online:2013-09-26 Published:2013-09-17
  • Contact: YANG Xiaocui E-mail:yxc0622@163.com

摘要:

采用基于密度泛函的第一性原理方法, 计算镧系氮化物的弹性性质、 光学性质和Debye[KG*8]温度. 计算结果表明: 轻镧系元素(Ln=La,Ce,Pr,Nd,Pm,Sm,Eu)氮化物(除LaN外)的体弹模量B与剪切模量G的比值均大于1.75; 重镧系金属元素(Ln=Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu)氮化物(除GdN外)的B/G均小于1.75; HoN晶体具有较高的介电常数和光学反射率; LaN晶体具有较高的折射率; 镧系氮化物的Debye温度为300~500 K, 即声子振动频率的数量级为1013 s-1.

关键词: 第一性原理计算, 弹性性质, 光学性质, Debye温度

Abstract:

The elastic, optical properties and Debye temperature of LnN were investigated by means of firstprinciples calculations based on density functional theory. The calculated elastic constants show that the B/G ratio of light LnN (Ln=La,Ce,Pr,Nd,Pm,Sm,Eu) is larger than 175 except LaN, indicating that th
ese crystals are ductile, while the ratio of heavy LnN (Ln=Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu) is smaller than 1.[KG-*3]75 except GdN, indicating that these crystals are brittle. The optical property shows that the static dielectric constant and reflection coefficient of HoN are the highest among those of all the LnN compounds, and shows that refractive index of LaN is the highest among those of all the LnN compounds. The Debye temperature of LnN is between 300—500 K, indicating that the order of magnitude of the phonon vibration is 1013 s-1.

Key words:  firstprinciples calculations, elastic property, optical property, Debye temperature

中图分类号: 

  • O482.1