Bridgmanite
Mg0.9Al0.2Si0.9O3
third-order Birch-Murnaghan · Original · 2000
Why this differs from similar rows?
Fits K_T0' freely from all volume data (7.2, poorly constrained since compression is under 4%); sibling row fixes K_T0' to 4 instead.
V₀
163.6
ų
Unit cell
K₀
215.400
GPa
Isothermal
K′
7.200
dimensionless
Volume (V₀)
| Value | Unit | Basis | Z |
|---|---|---|---|
| 163.6 | ų | Unit cell | — |
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 | 0.9 |
| Al2O3 | 0.1 |
| SiO2 | 0.9 |
Formula: Mg0.9Al0.2Si0.9O3
Conditions & method
- Tref
- —
- Pref
- —
- Structure
- orthorhombic perovskite (Pbnm/Pnma)
- Method
- experiment (XRD / DAC / multianvil compression)in situ synchrotron X-ray diffraction in diamond anvil cell (angle-dispersive, imaging plate), 4:1 methanol-ethanol pressure medium, hydrostatic to 9 GPa
- Sample
- sintered polycrystalline perovskite synthesized at 27 GPa, 2000 °C (run en90G3, Kubo 22)
Source
- Paper
- Compressibility of Mg<sub>0.9</sub>Al<sub>0.2</sub>Si&l…
- Authors
- Atsushi Kubo; Takehiko Yagi; Shigeaki Ono; Masaki Akaogi
- DOI
- 10.2183/pjab.76.103
- Year
- 2000
- Journal
- Proceedings of the Japan Academy Series B
- Origin
- Original (measured or fitted in the source paper)
Evidence from the paper
All the volume data for perovskite listed in Table I were fitted by the third-order Birch-Murnaghan equation of state, and we obtained K_T0 = 215.4 ± 4.4 GPa and K_T0' = 7.2 ± 1.4. Table I: ap107 0.00 (atmospheric) V = 163.6 (4) Å3; ku117 0.00 V = 163.5 (5) Å3.
Additional notes
second ambient V0
163.5 (5) Å3 (run ku117)
note
pressure range < 4% volume compression, so K' not well constrained
axial compressibilities
beta_a = 1.48(2)e-3 GPa^-1, beta_b = 1.19(3)e-3 GPa^-1, beta_c = 1.49(3)e-3 GPa^-1