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The relative strength of perovskite and post-perovskite NaCoF3

Published online by Cambridge University Press:  05 July 2018

D. P. Dobson ,
R. McCormack ,
S. A. Hunt ,
M. W. Ammann ,
D. Weidner ,
L Li  and
L. Wang
D. P. Dobson*
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK Institut für Geochemie und Petrologie, ETH Zürich, Sonneggstrasse 5, 8092 Zürich, Switzerland
R. McCormack
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
S. A. Hunt
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK Mineral Physics Institute, Department of Earth and Space Sciences, Stony Brook University, Stony Brook, New York, USA
M. W. Ammann
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
D. Weidner
Affiliation:
Mineral Physics Institute, Department of Earth and Space Sciences, Stony Brook University, Stony Brook, New York, USA
L Li
Affiliation:
Mineral Physics Institute, Department of Earth and Space Sciences, Stony Brook University, Stony Brook, New York, USA
L. Wang
Affiliation:
Mineral Physics Institute, Department of Earth and Space Sciences, Stony Brook University, Stony Brook, New York, USA HiPSEC and Department of Physics, University of Nevada, Las Vegas 89154-4002, Nevada, USA
*
*E-mail: [email protected]
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Abstract

Stable perovskite and metastable post-perovskite NaCoF3 were deformed in pure-shear geometry in a deformation-DIA press with radiographic monitoring of the sample strain. In isothermal experiments where there was no transformation, post-perovskite was found to be 5 times weaker than perovskite. In temperature-ramping experiments where post-perovskite transformed to perovskite during the deformation experiment the initial post-perovskite sample was 5–10 times weaker than perovskite under comparable conditions and their strengths converged during the transformation, being equal on completion of the transformation. These results confirm recent findings which show that postperovskite is weaker than perovskite, regardless of the prior history of the sample.

Keywords

perovskitepost-perovskitemantle rocksD” rheologyviscosity
Type
Research Article
Information
Mineralogical Magazine , Volume 76 , Issue 4 , August 2012 , pp. 925 - 932
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2012

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References

Ammann, M.W., Brodholt, J.P., Wookey, J. and Dobson, D.P. (2010) First-principles constraints on diffusion in lower-mantle minerals and a weak D layer. Nature, 465, 462–465.CrossRefGoogle Scholar
Cadek, O. and Fleitout, L. (2005) Effect of lateral viscosity variations in the core—mantle boundary region on predictions of the long-wavelength geoid. Studia Geophysica et Geodaetica, 50, 217–232.CrossRefGoogle Scholar
Catalli, K., Shim, S.-H. and Prakapenka, V. (2009) Thickness and Clapeyron slope of the post-perovskite boundary. Nature, 462, 782–786.CrossRefGoogle ScholarPubMed
Dobson, D.P., Hunt, S.A., Lindsay-Scott, A. and Wood, I.G. (2011) Towards better analogues for MgSiO3post-perovskite: NaCoF3 and NaNiF3, two new recoverable fluoride post-perovskites. Physics of the Earth and Planetary Interiors, 189, 171–175.CrossRefGoogle Scholar
Hernlund, J.W., Thomas, C. and Tackley, P.J. (2005) A doubling of the post-perovskite phase boundary and structure of the Earth's lowermost mantle. Nature, 434, 882–886.CrossRefGoogle ScholarPubMed
Hulse, CO. and Pask, A. (1960) Mechanical properties of magnesia single crystals in compressio. Journal of the American Ceramic Society, 43, 373–378.CrossRefGoogle Scholar
Hulse, CO., Copley, S.M. and Pask, J.A. (1963) Effect of crystal orientation on plastic deformation of magnesium oxide. Journal of the American Ceramic Society, 46, 317–323.CrossRefGoogle Scholar
Hunt, S.A., Weidner, D.J., Li, L., Wang, L., Walte, N.P. Brodholt, J.P. and Dobson, D.P. (2009) Weakening of CaIrO3 during the perovskite-post perovskite transformation. Nature Geoscience, 2, 794–797.CrossRefGoogle Scholar
Li, L., Raterron, P., Weidner, D. I and Chen, J. (2003) Olivine flow mechanisms at 8 GPa. Physics of the Earth and Planetary Interiors, 138, 113–129.CrossRefGoogle Scholar
Murakami, M., Hirose, K., Kawamura, K., Sata, N. and Ohishi, Y. (2004) Post perovskite phase transition in MgSiO3 . Science, 304, 855–858.CrossRefGoogle ScholarPubMed
Oganov, A.R. and Ono, S. (2004) Theoretical and experimental evidence for a post-perovskite phase of MgSiO3 in Earth's D’’ layer. Nature, 430, 445–448.CrossRefGoogle Scholar
Tosi, N., Cadek, O., Martinec, Z., Yuen, D.A., and Kaufmann, G. (2009) Is the long-wavelength geoid sensitive to the presence of postperovskite above the core-mantle boundary? Geophysical Research Letters, 36. http://dx.doi.org/10.1029/2008GL036902.CrossRefGoogle Scholar
Wang, Y., Durham, W.B., Getting, I.C and Weidner, D.J. (2003) The deformation-DIA: a new apparatus for high temperature triaxial deformation to pressures up to 15 GPa. Review of Scientific Instruments, 74, 3002–3011.Google Scholar
Wookey, J., Stackhouse, S., Kendall, J.-M., Brodholt, J. and Price, GD. (2005) Efficacy of the post-perovskite phase as an explanation for lowermost-mantle seismic properties. Nature, 438, 1004–1007.CrossRefGoogle ScholarPubMed