Phonon Density of States and Sound Velocities of Magnesiow?stite in Earth's Lower Mantle
The partial phonon densities of states of iron in magnesiowuestite [(Mg{sub 0.75},Fe{sub 0.25})O] have been measured by nuclear inelastic X-ray scattering up to 109 GPa. Compressional and shear wave velocities, shear moduli, and their pressure derivatives increase significantly across the spin-pairing transition of iron in (Mg{sub 0.75},Fe{sub 0.25})O at approximately 50 GPa. The effects of the transition on the elastic properties of (Mg,Fe)O at lower-mantle pressures are in contrast to what was predicted by studying MgO and high-spin magnesiowuestite, and need to be considered in future geophysical modeling of the lower mantle. The transition also affects other thermodynamic properties of magnesiowuestite under high pressures.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 898494
- Report Number(s):
- UCRL-JRNL-218397; TRN: US0701665
- Journal Information:
- Geophysical Research Letters, vol. 33, N/A, November 18, 2006, L22304, Journal Name: Geophysical Research Letters, vol. 33, N/A, November 18, 2006, L22304
- Country of Publication:
- United States
- Language:
- English
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