In-situ synchrotron X-ray diffraction study of scorodite at high pressure
Dawei Fan, Maining Ma, Shuyi Wei, BaoSheng Li, Zhiqiang Chen and Hongsen Xie
The compression behavior of a natural scorodite has been investigated to about 8.21 GPa at 300 K for the fist time using in situ angle-dispersive X-ray diffraction and a diamond anvil cell at beamline X17C, National Synchrotron Light Source, Brookhaven National Laboratory. Over this pressure range, no phase change or disproportionation has been observed. The isothermal equation of state was determined for the first time. The values of V0, K0, and K′0 refined with a third-order Birch-Murnaghan equation of state are V0, = 934.2 ± 0.3 Å3, K0, = 61.8 ± 2.5 GPa, and K′0 = 6.6 ± 0.9. Furthermore, we confirm that the linear compressibilities (β) along a, b and c directions of scorodite is elastically anisotropic.
Keywords: Scorodite, synchrotron X-ray diffraction, equation of state, high pressure, compressibility.