This study demonstrates the use of monochromatic synchrotron X-ray radiation of 40 keV for high-precision equation-of-state studies on sets of single crystals analysed individually in the same diamond-anvil pressure cell. Angle-dispersive zone-axis diffraction patterns were obtained from crystals of wustite-Fe0.93O and magnesiowüstite-(Mg0.73Fe 0.27)O to 51 GPa in a hydrostatic helium pressure medium. The rhombohedral phase of Fe0.93O was observed above 23 GPa, and its isothermal bulk modulus (K0) was determined to be 134 (±4) GPa, assuming K′ = 4. The rhombohedral phase of Fe0.93O is more compressible than B1-structured Fe0.93O, with K0 = 146 (±2) GPa. Magnesiowüstite-(Mg0.73Fe0.27)O remains cubic over the experimental pressure range, and has a bulk modulus of 154 (±3) GPa with K′ = 4.0 (±0.1).
- Diamond-anvil cell
- Equation of state
- Helium pressure medium
- Single-crystal X-ray diffraction
- Zone-axis diffraction
ASJC Scopus subject areas
- Nuclear and High Energy Physics