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

Lei Hao Feng, Qi Wei Hu, Li Lei, Lei Ming Fang, Lei Qi, Lei Lei Zhang, Mei Fang Pu, Zi Li Kou, Fang Peng, Xi Ping Chen, Yuan Hua Xia, Yohei Kojima, Hiroaki Ohfuji, Duan Wei He, Bo Chen, Tetsuo Irifune

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Tantalum nitride (TaN) compact with a Vickers hardness of 26 GPa is prepared by a high-pressure and hightemperature (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 BirchMurnaghan equation of state fitted to the x-ray diffraction pressure- volume (PV) sets of data, collected up to 41 GPa, yields ambient pressure isothermal bulk moduli of B0 = 369(2) GPa with pressure derivatives of B0 0 = 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 TaN 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.

Original languageEnglish
Article number026201
JournalChinese Physics B
Volume27
Issue number2
DOIs
Publication statusPublished - 2018 Feb
Externally publishedYes

Keywords

  • TaN
  • high pressure
  • neutron powder diffraction
  • synchrotron x-ray diffraction

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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