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Title: Elasticity of MgO to 11 GPa with an independent absolute pressure scale: Implications for pressure calibration

Abstract

P and S wave velocities and unit cell parameters (density) of MgO are measured simultaneously up to 11 GPa using combined ultrasonic interferometry and in situ X-ray diffraction techniques. The elastic bulk and shear moduli as well as their pressure derivatives are obtained by fitting the measured velocity and density data to the third-order finite strain equations, yielding K0S = 163.5(11) GPa, K'0S = 4.20(10), G0 = 129.8(6) GPa, and G'0 = 2.42(6), independent of pressure. These properties are subsequently used in a Birch-Murnaghan equation of state to determine the sample pressures at the observed strains. Comparison of the 300K isothermal compression of MgO indicates that current pressure scales from recent studies are in better than 1.5% agreement. We find that pressures derived from secondary pressure standards (NaCl, ruby fluorescence) at 300K are lower than those from current MgO scales by 5-8% ({approx}6% on average) in the entire pressure range of the current experiment. If this is taken into account, discrepancy in previous static compression studies on MgO at 300K can be reconciled, and a better agreement with the present study can be achieved.

Authors:
; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
980178
Report Number(s):
BNL-93096-2010-JA
Journal ID: ISSN 0148-0227; JGREA2; TRN: US201015%%1563
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Geophysical Research; Journal Volume: 111
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CALIBRATION; COMPRESSION; ELASTICITY; FLUORESCENCE; INTERFEROMETRY; PRESSURE RANGE; RUBY; S WAVES; SHEAR; STRAINS; ULTRASONIC WAVES; VELOCITY; X-RAY DIFFRACTION; P WAVES; national synchrotron light source

Citation Formats

Li, B., Woody, K, and Kung, J. Elasticity of MgO to 11 GPa with an independent absolute pressure scale: Implications for pressure calibration. United States: N. p., 2006. Web. doi:10.1029/2005JB004251.
Li, B., Woody, K, & Kung, J. Elasticity of MgO to 11 GPa with an independent absolute pressure scale: Implications for pressure calibration. United States. doi:10.1029/2005JB004251.
Li, B., Woody, K, and Kung, J. Sun . "Elasticity of MgO to 11 GPa with an independent absolute pressure scale: Implications for pressure calibration". United States. doi:10.1029/2005JB004251.
@article{osti_980178,
title = {Elasticity of MgO to 11 GPa with an independent absolute pressure scale: Implications for pressure calibration},
author = {Li, B. and Woody, K and Kung, J},
abstractNote = {P and S wave velocities and unit cell parameters (density) of MgO are measured simultaneously up to 11 GPa using combined ultrasonic interferometry and in situ X-ray diffraction techniques. The elastic bulk and shear moduli as well as their pressure derivatives are obtained by fitting the measured velocity and density data to the third-order finite strain equations, yielding K0S = 163.5(11) GPa, K'0S = 4.20(10), G0 = 129.8(6) GPa, and G'0 = 2.42(6), independent of pressure. These properties are subsequently used in a Birch-Murnaghan equation of state to determine the sample pressures at the observed strains. Comparison of the 300K isothermal compression of MgO indicates that current pressure scales from recent studies are in better than 1.5% agreement. We find that pressures derived from secondary pressure standards (NaCl, ruby fluorescence) at 300K are lower than those from current MgO scales by 5-8% ({approx}6% on average) in the entire pressure range of the current experiment. If this is taken into account, discrepancy in previous static compression studies on MgO at 300K can be reconciled, and a better agreement with the present study can be achieved.},
doi = {10.1029/2005JB004251},
journal = {Journal of Geophysical Research},
number = ,
volume = 111,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
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