Extended Data Fig. 5: X-ray diffraction pattern of FeO2Hx at 113 GPa and quenched from 2000 K.
From: Superionic iron oxide–hydroxide in Earth’s deep mantle
Pressure is measured using the equation of state of Pt. The sample completely transformed into the Py-FeO2Hx phase. The top panel is an integrated pattern from the 2D unrolled x-ray diffraction pattern at the bottom. The wavelength of the x-rays is 0.4066 Å. The strong diffraction peaks from the Py-phase confirmed that the majority of the sample is Py-FeO2Hx. The lattice parameter of the Py-phase is a = 4.392 Å, standing for x = 0.87(8) from ref. 16. The remaining diffraction peaks could be indexed to the pressure medium (LiF) and very tiny amounts of ε-FeOOH. After heating, the pressure was equilibrated at 113 GPa and the electrical leads were checked by immersing the DAC into a liquid nitrogen cryostat. The slope of the temperature versus EC plot was positive, clearly showing four electrodes were safely connected to the non-metallic sample without a short circuit (Extended Data Fig. 9).
