中国物理B ›› 2018, Vol. 27 ›› Issue (2): 26201-026201.doi: 10.1088/1674-1056/27/2/026201

• SPECIAL TOPIC—Soft matter and biological physics (Review) • 上一篇    下一篇

Neutron powder diffraction and high-pressure synchrotron x-ray diffraction study of tantalum nitrides

Lei-hao Feng(冯雷豪), Qi-wei Hu(胡启威), Li Lei(雷力), Lei-ming Fang(房雷鸣), Lei Qi(戚磊), Lei-lei Zhang(张雷雷), Mei-fang Pu(蒲梅芳), Zi-li Kou(寇自力), Fang Peng(彭放), Xi-ping Chen(陈喜平), Yuan-hua Xia(夏元华), Yohei Kojima(小岛洋平), Hiroaki Ohfuji(大藤宏明), Duan-wei He(贺端威), Bo Chen(陈波), Tetsuo Irifune(入舩徹男)   

  1. 1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
    2. Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China;
    3. Geodynamics Research Center, Ehime University, Matsuyama 790-8577, Japan
  • 收稿日期:2017-11-29 修回日期:2017-12-12 出版日期:2018-02-05 发布日期:2018-02-05
  • 通讯作者: Li Lei E-mail:lei@scu.edu.cn
  • 基金资助:

    Project supported by the Research Foundation of Key Laboratory of Neutron Physics (Grant No. 2015BB03), the National Natural Science Foundation of China (Grant Nos. 11774247), the Science Foundation for Excellent Youth Scholars of Sichuan University (Grant No. 2015SCU04A04), and the Joint Usage/Research Center PRIUS (Ehime University, Japan) and Chinese Academy of Sciences (Grant No. 2017-BEPC-PT-000568).

Neutron powder diffraction and high-pressure synchrotron x-ray diffraction study of tantalum nitrides

Lei-hao Feng(冯雷豪)1, Qi-wei Hu(胡启威)1, Li Lei(雷力)1, Lei-ming Fang(房雷鸣)2, Lei Qi(戚磊)1, Lei-lei Zhang(张雷雷)1, Mei-fang Pu(蒲梅芳)1, Zi-li Kou(寇自力)1, Fang Peng(彭放)1, Xi-ping Chen(陈喜平)2, Yuan-hua Xia(夏元华)2, Yohei Kojima(小岛洋平)3, Hiroaki Ohfuji(大藤宏明)3, Duan-wei He(贺端威)1, Bo Chen(陈波)2, Tetsuo Irifune(入舩徹男)3   

  1. 1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China;
    2. Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China;
    3. Geodynamics Research Center, Ehime University, Matsuyama 790-8577, Japan
  • Received:2017-11-29 Revised:2017-12-12 Online:2018-02-05 Published:2018-02-05
  • Contact: Li Lei E-mail:lei@scu.edu.cn
  • About author:62.50.-p; 61.05.cp; 61.05.F-; 31.15.ae
  • Supported by:

    Project supported by the Research Foundation of Key Laboratory of Neutron Physics (Grant No. 2015BB03), the National Natural Science Foundation of China (Grant Nos. 11774247), the Science Foundation for Excellent Youth Scholars of Sichuan University (Grant No. 2015SCU04A04), and the Joint Usage/Research Center PRIUS (Ehime University, Japan) and Chinese Academy of Sciences (Grant No. 2017-BEPC-PT-000568).

摘要:

Tantalum nitride (TaN) compact with a Vickers hardness of 26 GPa is prepared by a high-pressure and high-temperature (HPHT) method. The crystal structure and atom occupations of WC-type TaN have been investigated by neutron powder diffraction, and the compressibility of WC-type TaN has been investigated by using in-situ high-pressure synchrotron x-ray diffraction. The third-order Birch-Murnaghan equation of state fitted to the x-ray diffraction pressure-volume (P-V) sets of data, collected up to 41 GPa, yields ambient pressure isothermal bulk moduli of B0=369(2) GPa with pressure derivatives of B0'=4 for the WC-type TaN. The bulk modulus of WC-type TaN is not in good agreement with the previous result (B0=351 GPa), which is close to the recent theoretical calculation result (B0=378 GPa). An analysis of the experiment results shows that crystal structure of WC-type TaN can be viewed as alternate stacking of Ta and N layers along the c direction, and the covalent Ta-N bonds between Ta and N layers along the c axis in the crystal structure play an important role in the incompressibility and hardness of WC-type TaN.

关键词: neutron powder diffraction, synchrotron x-ray diffraction, TaN, high pressure

Abstract:

Tantalum nitride (TaN) compact with a Vickers hardness of 26 GPa is prepared by a high-pressure and high-temperature (HPHT) method. The crystal structure and atom occupations of WC-type TaN have been investigated by neutron powder diffraction, and the compressibility of WC-type TaN has been investigated by using in-situ high-pressure synchrotron x-ray diffraction. The third-order Birch-Murnaghan equation of state fitted to the x-ray diffraction pressure-volume (P-V) sets of data, collected up to 41 GPa, yields ambient pressure isothermal bulk moduli of B0=369(2) GPa with pressure derivatives of B0'=4 for the WC-type TaN. The bulk modulus of WC-type TaN is not in good agreement with the previous result (B0=351 GPa), which is close to the recent theoretical calculation result (B0=378 GPa). An analysis of the experiment results shows that crystal structure of WC-type TaN can be viewed as alternate stacking of Ta and N layers along the c direction, and the covalent Ta-N bonds between Ta and N layers along the c axis in the crystal structure play an important role in the incompressibility and hardness of WC-type TaN.

Key words: neutron powder diffraction, synchrotron x-ray diffraction, TaN, high pressure

中图分类号:  (High-pressure effects in solids and liquids)

  • 62.50.-p
61.05.cp (X-ray diffraction) 61.05.F- (Neutron diffraction and scattering) 31.15.ae (Electronic structure and bonding characteristics)