β–Fe2O3 nanoparticles were synthesized by the thermally-induced solid-state reaction of NaCl with Fe2(SO4)3 in air, followed by post-processing separation based on the dissolution of all by-products in water as described previously. High-pressure X-ray powder diffraction experiments with synchrotron radiation were performed using a diamond anvil cell high-pressure apparatus. A powdered β-Fe2O3 sample was loaded into a 50–100 μm diameter hole that was drilled into a rhenium gasket. Several ruby crystals were also put into the sample chamber. No pressure-transmitting medium was used in this study. The applied pressure was determined by monitoring the fluorescence line of ruby and ranged from 0.1 MPa to 64.4 GPa. In all cases, the desired pressure was established by gradually increasing the applied pressure. At selected pressures, the sample was probed by angle-dispersive X-ray diffraction using the NE1A synchrotron beamline at the Photon Factory in Japan. A monochromatic incident X-ray beam with a wavelength of λ ≈ 0.41 Å was used. The X-ray beams were collimated to a diameter of 30 μm, and the angle-dispersive X-ray diffraction patterns were obtained on an imaging plate (Rigaku) with 3000 × 3000 pixels. The distance between the sample and the detector was ~320 mm. The observed intensities on the imaging plates were integrated as a function of 2θ in order to obtain conventional one-dimensional diffraction profiles; details of the experimental procedure are presented elsewhere. If you are looking for high quality, high purity, and cost-effective Iron oxide, or if you require the latest price, please feel free to email contact mis-asia.