Qiang He

Publications (2)2.43 Total impact

• Article: Equation of state of CAS phase to pressure of the uppermost lower mantle at ambient temperature

  Xi Liu, Qiang He, LiWei Deng, ShuangMeng Zhai, XiaoMin Hu, BaoSheng Li, LiFei Zhang, ZhiQiang Chen, Qiong Liu
  [show abstract] [hide abstract]
  ABSTRACT: The CAS phase is a major constituent phase for the continental crust and basaltic compositions at the P-T conditions of the Earth’s mantle, and potentially plays an important role in the geodynamic processes related to slab subduction. Its equation of state has been investigated here at ambient temperature up to about 25 GPa by using a diamond-anvil cell and synchrotron X-ray radiation. Its P-V data, fitted to the third-order Birch-Murnaghan equation, yield an isothermal bulk modulus (K T ) of 185 (9) GPa and first pressure derivative (K′ T ) of 7.2 (12). If K′ T is fixed at 4, the derived K T is 212 (4) GPa. Additionally, the CAS phase is strongly elastically anisotropic, with its a-axis direction much less compressible than c-axis direction: K T−a :K T−c = 2.19. Keywordsanisotropic elasticity–CAS phase–equation of state–synchrotron X-ray radiation
  Science China Earth Science 05/2012; 54(9):1394-1399. · 0.70 Impact Factor
• Article: Solid solution between lead fluorapatite and lead fluorvanadate apatite: mixing behavior, Raman feature and thermal expansivity

  Qiang He, Xi Liu, Xiaomin Hu, Sicheng Li, Hejing Wang
  [show abstract] [hide abstract]
  ABSTRACT: The solid solution between lead fluorapatite and lead fluorvanadate apatite, Pb10[(PO4)6-x (VO4) x ]F2 with x equal to 0, 1, 2, 3, 4, 5 and 6, was synthesized by solid-state reaction at 1atm and 700°C for 72h and characterized by scanning electronic microprobe, electronic microprobe analysis, micro-Raman spectroscopy, and powder X-ray diffraction. The volume-composition relationship at ambient temperature does not show significant deviation from the Vegard’s Law. The Raman spectrum data suggest that both P and V are identical on a C s site and both end-members show no apparent factor-group effect. The Raman frequency shift of the symmetric stretching vibration is linearly dependent on the composition. High temperature X-ray diffraction data, up to 600°C, suggest that the thermal expansion coefficients α a , α c , and α V also vary linearly with the compositions of the apatites. KeywordsLead fluorapatite–Lead fluorvanadate apatite–Raman spectrum–Solid solution–Thermal expansion
  Physics and Chemistry of Minerals 05/2012; 38(10):741-752. · 1.73 Impact Factor