post-aragonite CaCO3-Pmmn
CaCO3
third-order Birch-Murnaghan · Original · 2020
Why this differs from similar rows?
This study's unconstrained BM3 fit to 300 K P-V data (Table 1), all parameters free; other rows in this group fix V0 to DFT, use a 50 GPa reference pressure, or are P-V-T fits.
V₀
96.6
ų
Unit cell
K₀
162
GPa
Isothermal
K′
3.100
dimensionless
Volume (V₀)
| Value | Unit | Basis | Z |
|---|---|---|---|
| 96.6 | 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 |
|---|---|
| CaO | 1 |
| CO2 | 1 |
Formula: CaCO3
Conditions & method
- Tref
- 300 K
- Pref
- —
- Structure
- other / unspecified
- Method
- experiment (XRD / DAC / multianvil compression)synchrotron XRD in laser-heated diamond-anvil cell (PM: Ne), Au pressure scale (Fei et al. 2007)
- Sample
- This study, unconstrained 300 K fit (Table 1)
Source
- Paper
- Thermal equation of state of post-aragonite CaCO3-Pmmn
- Authors
- Mingda Lv; Jiachao Liu; Eran Greenberg; Vitali B. Prakapenka; Susannah M. Dorfman
- DOI
- 10.2138/am-2020-7279
- Year
- 2020
- Journal
- American Mineralogist
- Origin
- Original (measured or fitted in the source paper)
Evidence from the paper
We fit BM3 EoS without constraint, yielding V0 = 96.6(±4.8) Å3, KT0 = 162(±62) GPa, K'0 = 3.1(±1.1). Table 1: 96.6(48) | 162(62) | 3.1(11) | XRD (PM: Ne) | This study.
Additional notes
note
Unquenchable phase; 1 bar parameters obtained by extrapolation from high-pressure data
F E intercept
F_E(0) = 162(±2) GPa from f-F analysis, consistent with KT0