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Phase Egg

AlSiO3OH (measured: Al0.98(1)Si0.92(1)O3OH1.39(5))

third-order Birch-Murnaghan · Original · 2018

Why this differs from similar rows?

New single-crystal synchrotron XRD data from this study, fit with EoSFit7c; sibling row is a refit of previously published powder data (Vanpeteghem et al. 2003), a different dataset.

V₀
214.08
ų
Unit cell
K₀
153
GPa
Isothermal
K′
8.600
dimensionless

Volume (V₀)

Value Unit Basis Z
214.08 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

OxideMolar
Al2O30.5
SiO21
H2O0.5

Formula: AlSiO3OH

Conditions & method

Tref
Pref
Structure
other / unspecified
Method
experiment (XRD / DAC / multianvil compression)
high-pressure single-crystal synchrotron X-ray diffraction (DAC, neon pressure medium, up to 23.33 GPa)
Sample
single crystal, synthesis run S5050 (26 GPa, 1600 °C, multi-anvil)

Source

Paper
High-pressure single-crystal structural analysis of AlSiO3OH phase egg
Authors
Kirsten Schulze; Martha G. Pamato; Alexander Kurnosov; Tiziana Boffa Ballaran; Konstantin Glazyrin; Anna Pakhomova; Hauke Marquardt
DOI
10.2138/am-2018-6562
Year
2018
Journal
American Mineralogist
Origin
Original (measured or fitted in the source paper)

Evidence from the paper

The room-pressure unit-cell volume, V0, the bulk modulus, K0, and its pressure derivative, K0ʹ, were refined using the software EoSFit7c (Angel et al. 2014) resulting in the following EoS parameters: V0 = 214.08(17) Å3, K0 = 153(8) GPa, and K0ʹ = 8.6(1.3) (Table 2). Note that in the fitting procedure the unit-cell volume collected at room pressure was not considered.

Additional notes

Kp table value
Table 2 lists K′ = 8.6(1.2), while the text reports 8.6(1.3)
measured ambient unit cell volume
214.43(1) Å3 at 0.0001 GPa (Table 1, in-house Huber diffractometer; excluded from EoS fit)
axial moduli this study
{
  "a0": "7.1848(12) Å",
  "Ma0": "833(14) GPa",
  "M'a": "12 (second-order Birch-Murnaghan EoS, implied fixed)",
  "b0": "4.327(2) Å",
  "Mb0": "240(16) GPa",
  "M'b": "30(3)",
  "c0": "6.963(2) Å",
  "Mc0": "497(40) GPa",
  "M'c": "36(7)"
}
relevance note
Phase egg is stable in the transition zone and probably also in the upper lower mantle up to 26 GPa at 1460–1600 °C (Pamato et al. 2015); candidate for water transport into Earth's deep mantle