中国物理B ›› 2019, Vol. 28 ›› Issue (6): 68101-068101.doi: 10.1088/1674-1056/28/6/068101

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Structural stability and vibrational characteristics of CaB6 under high pressure

Mingkun Liu(刘明坤), Can Tian(田灿), Xiaoli Huang(黄晓丽), Fangfei Li(李芳菲), Yanping Huang(黄艳萍), Bingbing Liu(刘冰冰), Tian Cui(崔田)   

  1. State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
  • 收稿日期:2019-01-07 修回日期:2019-04-04 出版日期:2019-06-05 发布日期:2019-06-05
  • 通讯作者: Xiaoli Huang E-mail:huangxiaoli@jlu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 51572108, 51632002, 11504127, 11674122, 11574112, 11474127, and 11634004), the 111 Project, China (Grant No. B12011), the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT_15R23), and the National Found for Fostering Talents of Basic Science, China (Grant No. J1103202).

Structural stability and vibrational characteristics of CaB6 under high pressure

Mingkun Liu(刘明坤), Can Tian(田灿), Xiaoli Huang(黄晓丽), Fangfei Li(李芳菲), Yanping Huang(黄艳萍), Bingbing Liu(刘冰冰), Tian Cui(崔田)   

  1. State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
  • Received:2019-01-07 Revised:2019-04-04 Online:2019-06-05 Published:2019-06-05
  • Contact: Xiaoli Huang E-mail:huangxiaoli@jlu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 51572108, 51632002, 11504127, 11674122, 11574112, 11474127, and 11634004), the 111 Project, China (Grant No. B12011), the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT_15R23), and the National Found for Fostering Talents of Basic Science, China (Grant No. J1103202).

摘要:

In situ Raman spectroscopy and x-ray diffraction measurements are used to explore the structural stability of CaB6 at high pressures and room temperature. The results show no evidence of structural phase transitions up to at least 40 GPa. The obtained equation of state with smooth pressure dependencies yields a zero-pressure isothermal bulk modulus B0=170 (5) GPa, which agrees well with the previous measurements. The frequency shifts for A1g, Eg, and T2g vibrational modes of polycrystalline CaB6 are obtained with pressure uploading. As the pressure increases, all the vibration modes have smooth monotonic pressure dependence. The Grüneisen parameter of Eg modes is the largest, indicating its largest dependence on the volume of a crystal lattice.

关键词: CaB6, high pressure, diamond anvil cell, structural stability

Abstract:

In situ Raman spectroscopy and x-ray diffraction measurements are used to explore the structural stability of CaB6 at high pressures and room temperature. The results show no evidence of structural phase transitions up to at least 40 GPa. The obtained equation of state with smooth pressure dependencies yields a zero-pressure isothermal bulk modulus B0=170 (5) GPa, which agrees well with the previous measurements. The frequency shifts for A1g, Eg, and T2g vibrational modes of polycrystalline CaB6 are obtained with pressure uploading. As the pressure increases, all the vibration modes have smooth monotonic pressure dependence. The Grüneisen parameter of Eg modes is the largest, indicating its largest dependence on the volume of a crystal lattice.

Key words: CaB6, high pressure, diamond anvil cell, structural stability

中图分类号:  (Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides))

  • 81.05.Je
81.05.ug (Diamond) 91.65.Pj (Ultra-high pressure metamorphism) 64.60.-i (General studies of phase transitions)