Bridgmanite
MgSiO3
unknown · Original · 1991
V₀
24.725
cm³
Molar
K₀
246.500
GPa
Unknown
K′
4
dimensionless
Volume (V₀)
| Value | Unit | Basis | Z |
|---|---|---|---|
| 24.725 | cm³ | Molar | — |
Reported value and unit are preserved as extracted. Z (formula units per cell) is not stored yet, so molar ↔ ų/f.u. conversion is not applied automatically.
Composition
| Oxide | Molar |
|---|---|
| MgO | 1 |
| SiO2 | 1 |
Formula: MgSiO3
Conditions & method
- Tref
- 300 K
- Pref
- —
- Structure
- orthorhombic perovskite (Pbnm/Pnma)
- Method
- experiment (Brillouin / ultrasonic / elasticity)energy-dispersive synchrotron x-ray diffraction in large-volume press; model parameters partly adopted from Brillouin spectroscopy (ref 16)
- Sample
- polycrystalline MgSiO3 perovskite synthesized at 26 GPa and 2273 K (USSA-2000)
Source
- Paper
- Phase Transition and Thermal Expansion of MgSiO 3 Perovskite
- Authors
- Yanbin Wang; Donald J. Weidner; Robert C. Liebermann; Xing Liu; Jaidong Ko; Michael T. Vaughan; Yusheng Zhao; Amir Yeganeh‐Haeri; Rosemary E. G. Pacalo
- DOI
- 10.1126/science.251.4992.410
- Year
- 1991
- Journal
- Science
- Origin
- Original (measured or fitted in the source paper)
Evidence from the paper
The high-temperature phase is assumed to be stable at 1071 km with a room-temperature molar volume of 24.725 cm3 [=V0^Pbnm(1+0.7%)]; K0=246.5 GPa (16); (dK/dP)0=4. With these parameters we infer an iron-content of 10.4% at 1071 km by matching the seismic density.
Additional notes
K0 source
cited from reference (16), Brillouin spectroscopy data at 1 bar
V0 derivation
V0^Pbnm increased by 0.7% to account for the phase transition volume increase
alpha v high T phase
1.5 x 10^-5 K^-1 (this study, used in Fig. 4 model)
model context
Fig. 4 lower-mantle density model at 1071 km depth; density 4.621 g cm^-3, pressure 41.86 GPa (PREM), temperature 2004 K; inferred iron content 10.4% for pyrolite stoichiometry