Behavior of epidote at high pressure and high temperature

A powder diffraction study up to 10 GPa and 1,200 K

G. Diego Gatta, Marco Merlini, Yongjae Lee, Stefano Poli

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The thermo-elastic behavior of a natural epidote [Ca1.925 Fe0.745Al2.265Ti0.004Si3.037O12(OH)] has been investigated up to 1,200 K (at 0.0001 GPa) and 10 GPa (at 298 K) by means of in situ synchrotron powder diffraction. No phase transition has been observed within the temperature and pressure range investigated. P-V data fitted with a third-order Birch-Murnaghan equation of state (BM-EoS) give V0 = 458.8(1)Å3, KT0 = 111(3) GPa, and K′ = 7.6(7). The confidence ellipse from the variance-covariance matrix of KT0 and K′ from the least-square procedure is strongly elongated with negative slope. The evolution of the "Eulerian finite strain" vs "normalized stress" yields Fe(0) = 114(1) GPa as intercept values, and the slope of the regression line gives K′ = 7.0(4). The evolution of the lattice parameters with pressure is slightly anisotropic. The elastic parameters calculated with a linearized BM-EoS are: a0 = 8.8877(7) Å, KT0(a) = 117(2) GPa, and K′(a) = 3.7(4) for the a-axis; b0 = 5.6271(7) Å, KT0(b) = 126(3) GPa, and K′(b) = 12(1) for the b-axis; and c0 = 10.1527(7) Å, KT0(c) = 90(1) GPa, and K'(c) = 8.1(4) for the c-axis [KT0(a):KT0(b):KT0(c) = 1.30:1.40:1]. The β angle decreases with pressure, βP(°) = βP0 -0.0286(9)P +0.00134(9)P2 (P in GPa). The evolution of axial and volume thermal expansion coefficient, α, with T was described by the polynomial function: α(T) = α0 + α1T-1/2. The refined parameters for epidote are: α0 = 5.1(2) × 10-5 K-1 and α1 = -5.1(6) × 10-4 K1/2 for the unit-cell volume, α0(a) = 1.21(7) × 10-5 K-1 and α1(a) = -1.2(2) × 10-4 K1/2 for the a-axis, α0(b) = 1.88(7) × 10-5 K-1 and α1(b) = -1.7(2) × 10-4 K1/2 for the b-axis, and α0(c) = 2.14(9) × 10-5 K-1 and α1(c) = -2.0(2) × 10-4 K1/2 for the c-axis. The thermo-elastic anisotropy can be described, at a ry α0(a): α0(b): α0(c) =1'G.D:1.55:1.77. The β angle increases continuously with T, with βT(°) = βT0 + 2.5(1) × 10-4T + 1.3(7) × 10-8T2. A comparison between the thermo-elastic parameters of epidote and clinozoisite is carried out.

Original languageEnglish
Pages (from-to)419-428
Number of pages10
JournalPhysics and Chemistry of Minerals
Volume38
Issue number6
DOIs
Publication statusPublished - 2011 Jun 1

Fingerprint

epidote
diffraction
Equations of state
equation of state
Covariance matrix
clinozoisite
Synchrotrons
Temperature
Lattice constants
Thermal expansion
Yield stress
thermal expansion
ellipse
Anisotropy
phase transition
Phase transitions
Polynomials
anisotropy
matrix
parameter

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Geochemistry and Petrology

Cite this

@article{3e51d84b766e45d58f1a8f3da51e171d,
title = "Behavior of epidote at high pressure and high temperature: A powder diffraction study up to 10 GPa and 1,200 K",
abstract = "The thermo-elastic behavior of a natural epidote [Ca1.925 Fe0.745Al2.265Ti0.004Si3.037O12(OH)] has been investigated up to 1,200 K (at 0.0001 GPa) and 10 GPa (at 298 K) by means of in situ synchrotron powder diffraction. No phase transition has been observed within the temperature and pressure range investigated. P-V data fitted with a third-order Birch-Murnaghan equation of state (BM-EoS) give V0 = 458.8(1){\AA}3, KT0 = 111(3) GPa, and K′ = 7.6(7). The confidence ellipse from the variance-covariance matrix of KT0 and K′ from the least-square procedure is strongly elongated with negative slope. The evolution of the {"}Eulerian finite strain{"} vs {"}normalized stress{"} yields Fe(0) = 114(1) GPa as intercept values, and the slope of the regression line gives K′ = 7.0(4). The evolution of the lattice parameters with pressure is slightly anisotropic. The elastic parameters calculated with a linearized BM-EoS are: a0 = 8.8877(7) {\AA}, KT0(a) = 117(2) GPa, and K′(a) = 3.7(4) for the a-axis; b0 = 5.6271(7) {\AA}, KT0(b) = 126(3) GPa, and K′(b) = 12(1) for the b-axis; and c0 = 10.1527(7) {\AA}, KT0(c) = 90(1) GPa, and K'(c) = 8.1(4) for the c-axis [KT0(a):KT0(b):KT0(c) = 1.30:1.40:1]. The β angle decreases with pressure, βP(°) = βP0 -0.0286(9)P +0.00134(9)P2 (P in GPa). The evolution of axial and volume thermal expansion coefficient, α, with T was described by the polynomial function: α(T) = α0 + α1T-1/2. The refined parameters for epidote are: α0 = 5.1(2) × 10-5 K-1 and α1 = -5.1(6) × 10-4 K1/2 for the unit-cell volume, α0(a) = 1.21(7) × 10-5 K-1 and α1(a) = -1.2(2) × 10-4 K1/2 for the a-axis, α0(b) = 1.88(7) × 10-5 K-1 and α1(b) = -1.7(2) × 10-4 K1/2 for the b-axis, and α0(c) = 2.14(9) × 10-5 K-1 and α1(c) = -2.0(2) × 10-4 K1/2 for the c-axis. The thermo-elastic anisotropy can be described, at a ry α0(a): α0(b): α0(c) =1'G.D:1.55:1.77. The β angle increases continuously with T, with βT(°) = βT0 + 2.5(1) × 10-4T + 1.3(7) × 10-8T2. A comparison between the thermo-elastic parameters of epidote and clinozoisite is carried out.",
author = "Gatta, {G. Diego} and Marco Merlini and Yongjae Lee and Stefano Poli",
year = "2011",
month = "6",
day = "1",
doi = "10.1007/s00269-010-0415-y",
language = "English",
volume = "38",
pages = "419--428",
journal = "Physics and Chemistry of Minerals",
issn = "0342-1791",
publisher = "Springer Verlag",
number = "6",

}

Behavior of epidote at high pressure and high temperature : A powder diffraction study up to 10 GPa and 1,200 K. / Gatta, G. Diego; Merlini, Marco; Lee, Yongjae; Poli, Stefano.

In: Physics and Chemistry of Minerals, Vol. 38, No. 6, 01.06.2011, p. 419-428.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Behavior of epidote at high pressure and high temperature

T2 - A powder diffraction study up to 10 GPa and 1,200 K

AU - Gatta, G. Diego

AU - Merlini, Marco

AU - Lee, Yongjae

AU - Poli, Stefano

PY - 2011/6/1

Y1 - 2011/6/1

N2 - The thermo-elastic behavior of a natural epidote [Ca1.925 Fe0.745Al2.265Ti0.004Si3.037O12(OH)] has been investigated up to 1,200 K (at 0.0001 GPa) and 10 GPa (at 298 K) by means of in situ synchrotron powder diffraction. No phase transition has been observed within the temperature and pressure range investigated. P-V data fitted with a third-order Birch-Murnaghan equation of state (BM-EoS) give V0 = 458.8(1)Å3, KT0 = 111(3) GPa, and K′ = 7.6(7). The confidence ellipse from the variance-covariance matrix of KT0 and K′ from the least-square procedure is strongly elongated with negative slope. The evolution of the "Eulerian finite strain" vs "normalized stress" yields Fe(0) = 114(1) GPa as intercept values, and the slope of the regression line gives K′ = 7.0(4). The evolution of the lattice parameters with pressure is slightly anisotropic. The elastic parameters calculated with a linearized BM-EoS are: a0 = 8.8877(7) Å, KT0(a) = 117(2) GPa, and K′(a) = 3.7(4) for the a-axis; b0 = 5.6271(7) Å, KT0(b) = 126(3) GPa, and K′(b) = 12(1) for the b-axis; and c0 = 10.1527(7) Å, KT0(c) = 90(1) GPa, and K'(c) = 8.1(4) for the c-axis [KT0(a):KT0(b):KT0(c) = 1.30:1.40:1]. The β angle decreases with pressure, βP(°) = βP0 -0.0286(9)P +0.00134(9)P2 (P in GPa). The evolution of axial and volume thermal expansion coefficient, α, with T was described by the polynomial function: α(T) = α0 + α1T-1/2. The refined parameters for epidote are: α0 = 5.1(2) × 10-5 K-1 and α1 = -5.1(6) × 10-4 K1/2 for the unit-cell volume, α0(a) = 1.21(7) × 10-5 K-1 and α1(a) = -1.2(2) × 10-4 K1/2 for the a-axis, α0(b) = 1.88(7) × 10-5 K-1 and α1(b) = -1.7(2) × 10-4 K1/2 for the b-axis, and α0(c) = 2.14(9) × 10-5 K-1 and α1(c) = -2.0(2) × 10-4 K1/2 for the c-axis. The thermo-elastic anisotropy can be described, at a ry α0(a): α0(b): α0(c) =1'G.D:1.55:1.77. The β angle increases continuously with T, with βT(°) = βT0 + 2.5(1) × 10-4T + 1.3(7) × 10-8T2. A comparison between the thermo-elastic parameters of epidote and clinozoisite is carried out.

AB - The thermo-elastic behavior of a natural epidote [Ca1.925 Fe0.745Al2.265Ti0.004Si3.037O12(OH)] has been investigated up to 1,200 K (at 0.0001 GPa) and 10 GPa (at 298 K) by means of in situ synchrotron powder diffraction. No phase transition has been observed within the temperature and pressure range investigated. P-V data fitted with a third-order Birch-Murnaghan equation of state (BM-EoS) give V0 = 458.8(1)Å3, KT0 = 111(3) GPa, and K′ = 7.6(7). The confidence ellipse from the variance-covariance matrix of KT0 and K′ from the least-square procedure is strongly elongated with negative slope. The evolution of the "Eulerian finite strain" vs "normalized stress" yields Fe(0) = 114(1) GPa as intercept values, and the slope of the regression line gives K′ = 7.0(4). The evolution of the lattice parameters with pressure is slightly anisotropic. The elastic parameters calculated with a linearized BM-EoS are: a0 = 8.8877(7) Å, KT0(a) = 117(2) GPa, and K′(a) = 3.7(4) for the a-axis; b0 = 5.6271(7) Å, KT0(b) = 126(3) GPa, and K′(b) = 12(1) for the b-axis; and c0 = 10.1527(7) Å, KT0(c) = 90(1) GPa, and K'(c) = 8.1(4) for the c-axis [KT0(a):KT0(b):KT0(c) = 1.30:1.40:1]. The β angle decreases with pressure, βP(°) = βP0 -0.0286(9)P +0.00134(9)P2 (P in GPa). The evolution of axial and volume thermal expansion coefficient, α, with T was described by the polynomial function: α(T) = α0 + α1T-1/2. The refined parameters for epidote are: α0 = 5.1(2) × 10-5 K-1 and α1 = -5.1(6) × 10-4 K1/2 for the unit-cell volume, α0(a) = 1.21(7) × 10-5 K-1 and α1(a) = -1.2(2) × 10-4 K1/2 for the a-axis, α0(b) = 1.88(7) × 10-5 K-1 and α1(b) = -1.7(2) × 10-4 K1/2 for the b-axis, and α0(c) = 2.14(9) × 10-5 K-1 and α1(c) = -2.0(2) × 10-4 K1/2 for the c-axis. The thermo-elastic anisotropy can be described, at a ry α0(a): α0(b): α0(c) =1'G.D:1.55:1.77. The β angle increases continuously with T, with βT(°) = βT0 + 2.5(1) × 10-4T + 1.3(7) × 10-8T2. A comparison between the thermo-elastic parameters of epidote and clinozoisite is carried out.

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