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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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