Compression, thermal expansion, structure, and instability of CaIrO3, the structure model of MgSiO3 post-perovskite

C. David Martin; Karena W. Chapman; Peter J. Chupas; Vitali Prakapenka; Peter L. Lee; Sarvjit D. Shastri; John B. Parise

doi:10.2138/am.2007.2473

Compression, thermal expansion, structure, and instability of CaIrO₃, the structure model of MgSiO₃ post-perovskite

C. David Martin
, Karena W. Chapman
, Peter J. Chupas
, Vitali Prakapenka
, Peter L. Lee
, Sarvjit D. Shastri
, John B. Parise

Stony Brook University
United States Department of Energy

Research output: Contribution to journal › Article › peer-review

34 Scopus citations

Abstract

Analysis of pressure-temperature dependent monochromatic X-ray powder diffraction data yield the bulk modulus [K_T, = 180.2(28) GPa] and thermal expansion coefficients [α₀ = 2.841(34) × 10^-5 K^-1; α¹ = 3.37(48) × 10^-9 K^-2] of CaIrO₃, the structure model for post-perovskite MgSiO₃. CaIrO₃ is orthorhombic (Cmcm, space group 63, Z = 4) with best-fit unit-cell parameters, α = 3.14147(5) Å, b = 9.87515(19), c = 7.29711(11), and V = 226.3754(78) Å³ at 1 bar and 300 K. The c-axis of CaIrO₃ has a small compressibility and a large thermal expansion when compared to the other principal axes. Rietveld structure refinement reveals changes in CaIrO₃ as a function of temperature in terms Of IrO₆ octahedra distortion. Dissociation of CaIrO₃ at high temperature has possible implications for the post-perovskite MgSiO₃ structure, Earth's lower mantle, and D" layer.

Original language	English
Pages (from-to)	1048-1053
Number of pages	6
Journal	American Mineralogist
Volume	92
Issue number	7
DOIs	https://doi.org/10.2138/am.2007.2473
State	Published - Jul 2007

Keywords

CaIrO
D" layer
Post-perovskite
Pressure
Rietveld refinement
Structure
Temperature
X-rays

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10.2138/am.2007.2473

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@article{6f11f60be941458e834c03115c749627,

title = "Compression, thermal expansion, structure, and instability of CaIrO3, the structure model of MgSiO3 post-perovskite",

abstract = "Analysis of pressure-temperature dependent monochromatic X-ray powder diffraction data yield the bulk modulus [KT, = 180.2(28) GPa] and thermal expansion coefficients [α0 = 2.841(34) × 10-5 K-1; α1 = 3.37(48) × 10-9 K-2] of CaIrO3, the structure model for post-perovskite MgSiO3. CaIrO3 is orthorhombic (Cmcm, space group 63, Z = 4) with best-fit unit-cell parameters, α = 3.14147(5) {\AA}, b = 9.87515(19), c = 7.29711(11), and V = 226.3754(78) {\AA}3 at 1 bar and 300 K. The c-axis of CaIrO3 has a small compressibility and a large thermal expansion when compared to the other principal axes. Rietveld structure refinement reveals changes in CaIrO3 as a function of temperature in terms Of IrO6 octahedra distortion. Dissociation of CaIrO3 at high temperature has possible implications for the post-perovskite MgSiO3 structure, Earth's lower mantle, and D{"} layer.",

keywords = "CaIrO, D{"} layer, Post-perovskite, Pressure, Rietveld refinement, Structure, Temperature, X-rays",

author = "Martin, \{C. David\} and Chapman, \{Karena W.\} and Chupas, \{Peter J.\} and Vitali Prakapenka and Lee, \{Peter L.\} and Shastri, \{Sarvjit D.\} and Parise, \{John B.\}",

year = "2007",

month = jul,

doi = "10.2138/am.2007.2473",

language = "English",

volume = "92",

pages = "1048--1053",

journal = "American Mineralogist",

issn = "0003-004X",

number = "7",

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TY - JOUR

T1 - Compression, thermal expansion, structure, and instability of CaIrO3, the structure model of MgSiO3 post-perovskite

AU - Martin, C. David

AU - Chapman, Karena W.

AU - Chupas, Peter J.

AU - Prakapenka, Vitali

AU - Lee, Peter L.

AU - Shastri, Sarvjit D.

AU - Parise, John B.

PY - 2007/7

Y1 - 2007/7

N2 - Analysis of pressure-temperature dependent monochromatic X-ray powder diffraction data yield the bulk modulus [KT, = 180.2(28) GPa] and thermal expansion coefficients [α0 = 2.841(34) × 10-5 K-1; α1 = 3.37(48) × 10-9 K-2] of CaIrO3, the structure model for post-perovskite MgSiO3. CaIrO3 is orthorhombic (Cmcm, space group 63, Z = 4) with best-fit unit-cell parameters, α = 3.14147(5) Å, b = 9.87515(19), c = 7.29711(11), and V = 226.3754(78) Å3 at 1 bar and 300 K. The c-axis of CaIrO3 has a small compressibility and a large thermal expansion when compared to the other principal axes. Rietveld structure refinement reveals changes in CaIrO3 as a function of temperature in terms Of IrO6 octahedra distortion. Dissociation of CaIrO3 at high temperature has possible implications for the post-perovskite MgSiO3 structure, Earth's lower mantle, and D" layer.

AB - Analysis of pressure-temperature dependent monochromatic X-ray powder diffraction data yield the bulk modulus [KT, = 180.2(28) GPa] and thermal expansion coefficients [α0 = 2.841(34) × 10-5 K-1; α1 = 3.37(48) × 10-9 K-2] of CaIrO3, the structure model for post-perovskite MgSiO3. CaIrO3 is orthorhombic (Cmcm, space group 63, Z = 4) with best-fit unit-cell parameters, α = 3.14147(5) Å, b = 9.87515(19), c = 7.29711(11), and V = 226.3754(78) Å3 at 1 bar and 300 K. The c-axis of CaIrO3 has a small compressibility and a large thermal expansion when compared to the other principal axes. Rietveld structure refinement reveals changes in CaIrO3 as a function of temperature in terms Of IrO6 octahedra distortion. Dissociation of CaIrO3 at high temperature has possible implications for the post-perovskite MgSiO3 structure, Earth's lower mantle, and D" layer.

KW - CaIrO

KW - D" layer

KW - Post-perovskite

KW - Pressure

KW - Rietveld refinement

KW - Structure

KW - Temperature

KW - X-rays

UR - https://www.scopus.com/pages/publications/34547423244

U2 - 10.2138/am.2007.2473

DO - 10.2138/am.2007.2473

M3 - Article

AN - SCOPUS:34547423244

SN - 0003-004X

VL - 92

SP - 1048

EP - 1053

JO - American Mineralogist

JF - American Mineralogist

IS - 7

ER -

Compression, thermal expansion, structure, and instability of CaIrO₃, the structure model of MgSiO₃ post-perovskite

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