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Post-perovskite

CaIrO3

third-order Birch-Murnaghan · Original · 2007

V₀
226.38
ų
Unit cell
K₀
181
GPa
Isothermal
K′
2.300
dimensionless

Volume (V₀)

Value Unit Basis Z
226.38 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

CaIrO3

Conditions & method

Tref
Pref
0.000 GPa
Structure
post-perovskite (CaIrO3-type, Cmcm)
Method
experiment (XRD / DAC / multianvil compression)
high-pressure single-crystal X-ray diffraction in diamond anvil cell (compression to ~7.8 GPa, methanol:ethanol medium, ruby pressure standard)
Sample
single crystal (170×70×50 μm) synthesized at 1435 °C and 1 GPa

Source

Paper
Equations of state of CaIrO3 perovskite and post-perovskite phases
Authors
Tiziana Boffa Ballaran; Reidar G. Trønnes; D. J. Frost
DOI
10.2138/am.2007.2715
Year
2007
Journal
American Mineralogist
Origin
Original (measured or fitted in the source paper)

Evidence from the paper

A third-order Birch Murnaghan equation of state has been used to fit the measured P-V data with the following refined parameters: ... V0 = 226.38(1) Å3, K0 = 181(3) GPa, K' = 2.3(8) for CaIrO3 ... post-perovskite ... Table 2: V0 (Å3) 226.38(1); K0 (GPa) 181(3); K' 2.3(8). Table 1 ambient row (Cmcm): 0.00010(1) GPa, V = 226.376(12) Å3.

Additional notes

axial BM3 parameters
{
  "a0_A": "3.1454(1)",
  "K0_a_GPa": "228(5)",
  "Kp_a": "4(1)",
  "beta0a_GPa-1": "0.00146",
  "b0_A": "9.8619(3)",
  "K0_b_GPa": "124(2)",
  "Kp_b": "0.9(5)",
  "beta0b_GPa-1": "0.00269",
  "c0_A": "7.2979(1)",
  "K0_c_GPa": "243(4)",
  "Kp_c": "5(1)",
  "beta0c_GPa-1": "0.00137"
}
F-f fit
FE = 181(2) - 433(214)fE
fitting software
Eosfit52 program (Angel 2002)
note
CaIrO3 post-perovskite is a low-pressure structural analogue for MgSiO3 post-perovskite in the lowermost mantle (D" layer); minor Ca(OH)2 detected in run products