Stability of the MgSiO3 analog NaMgF3 and its implication for mantle structure in super-Earths

@article{Grocholski2010StabilityOT,
  title={Stability of the MgSiO3 analog NaMgF3 and its implication for mantle structure in super-Earths},
  author={Brent Grocholski and Sang‐Heon Shim and Vitali B. Prakapenka},
  journal={Geophysical Research Letters},
  year={2010},
  volume={37}
}
[1] First-principles calculations on MgSiO3 suggested a breakdown into MgO + SiO2 at pressure above 1000 GPa with an extremely large negative Clapeyron slope, isolating the lowermost mantles of larger super-Earths (∼10M⊕) from convection. Similar calculations predicted the same type of breakdown in NaMgF3 to NaF + MgF2 at 40 GPa, allowing for experimental examination. We found that NaMgF3 is stable to at least 70 GPa and 2500 K. In our measurements on MgF2 (an SiO2 analog), we found a… 

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References

SHOWING 1-10 OF 37 REFERENCES
NaMgF 3 : A low-pressure analog of MgSiO 3
[1] Using first principles computations we show that NaMgF3 perovskite undergoes the same series of phase transitions as MgSiO3 perovskite, that is, the postperovskite transition and the dissociation
High-pressure phases in SnO2 to 117 GPa
X-ray diffraction of SnO2 cassiterite at high pressures and temperatures demonstrates the existence of four phase transitions to 117 GPa. The observed sequence of phases for SnO2 is rutile-type P42
Thickness and Clapeyron slope of the post-perovskite boundary
TLDR
The pPv boundary would be particularly thick in regions with an elevated Al content and/or a low Mg/Si ratio, reducing the effects of the large positive Clapeyron slope on the buoyancy of thermal anomalies and stabilizing compositional heterogeneities in the lowermost mantle.
High-pressure phases in SnO 2 to 117 GPa
X-ray diffraction of SnO2 cassiterite at high pressures and temperatures demonstrates the existence of four phase transitions to 117 GPa. The observed sequence of phases for SnO2 is rutile-type
Equation of state of NaMgF3 postperovskite: Implication for the seismic velocity changes in the D″ region
[1] Recent first-principles calculations have proposed that bulk sound speed (VΦ) decreases at the perovskite (Pv) → postperovskite (PPv) transition. Yet some measurements suggest an increase in VΦ
Phase relations and equation of state of ZrO2 to 100 GPa
The phase relations and equation of state of ZrO 2 were investigated up to 100 GPa by means of in situ observation using laser heating in a diamond anvil cell and synchrotron radiation. A cotunnite
NaMgF3: a low-pressure analog of MgSiO3
[1] Using first principles computations we show that NaMgF 3 perovskite undergoes the same series of phase transitions as MgSiO 3 perovskite, that is, the post-perovskite transition and the
Rietveld structure refinement of MgGeO3 post-perovskite phase to 1 Mbar
Abstract Using the CaIrO3-type structure model (space group Cmcm), lattice parameters and atomic positions of the MgGeO3 post-perovskite (pPv) phase were determined based on Rietveld refinements at
Structural Phase Transition of Rutile-Type MgH2 at High Pressures
The pressure-induced structural phase transition of MgH 2 was examined up to 57 GPa at room temperature. α-MgH 2 with the rutile-type structure at ambient conditions transformed to γ-MgH 2 with the
High-pressure structural phase transitions in magnesium fluoride studied by electronic structure calculations
Abstract The present work employs the self-consistent tight binding linear muffin tin orbital method (TB-LMTO) to calculate the electronic structure and the relative stability of MgF2. MgF2 is found
...
1
2
3
4
...