In-situ synchrotron powder X-ray diffraction study of vanadinite at room temperature and high pressure
Dawei Fan, Maining Ma, Shuyi Wei, Zhiqiang Chen and Hongsen Xie
The compression behavior of a natural vanadinite has been investigated using in situ angle-dispersive X-ray diffraction and a diamond anvil cell up to 8.74 GPa, respectively. No phase transition of vanadinite was observed within the experimental pressure range. The isothermal equation of state was determined. The values of K0, and K’0 refined with a third-order Birch- Murnaghan equation of state are K0 = 55 ± 1 GPa and K’0 = 6.1 ± 0.5 for vanadinite. Furthermore, we obtained that the axial compressibilities of the natural vanadinite (6.94 x 10-3 GPa-1 and 3.83 x 10-3 GPa-1 for the a– and c-axis of vanadinite, respectively). In addition, combining with previous results, the compositional dependence of the bulk modulus and its pressure derivative of vanadinite are discussed.
Keywords: High pressure, Synchrotron radiation X-ray diffraction, Equation of state, Vanadinite.