Extended Data Fig. 6: X-ray diffraction pattern of FeO2Hx at 121 GPa and quenched from 3000–3400 K.
From: Superionic iron oxide–hydroxide in Earth’s deep mantle
In the left panel, the pattern taken at the center of heating is still dominated by the Py-phase with lattice parameter a = 4.379 Å and corresponding x = 0.86(8) (ref. 16). The minor peaks in the pattern may associate with dhcp-FeHx and/or Cmcm-type Fe2O3. The reference lattices parameters are dhcp-FeHx (a = 2.458 Å, c = 8.046 Å); Cmcm-type Fe2O3 (a = 2.559 Å, a = 8.257 Å, c = 6.164 Å). Pressure is measured by the equation of state of Pt. The wavelength of the x-ray is 0.3344 Å. The right panel is an XRD mapping contour around the heating area. We first divided the heated portion of sample into (21 × 21 μm2) a 7 × 7 matrix. We collect one XRD pattern on each grid point with the same 10-seconds’ exposure time. Colors on the color bar are proportional to the intensity of Py-phase 111 peak. The contour is then constructed by interpolating those intensities.
