Lord, OT, Wan, ETH, Hunt, SA et al. (8 more authors) (2014) The NiSi melting curve to 70 GPa. Physics of the Earth and Planetary Interiors, 233. pp. 13-23. ISSN 0031-9201
Abstract
The melting curve of NiSi has been determined to 70 GPa on the basis of laser-heated diamond anvil cell (LH-DAC) experiments in which changes in the gradient of temperature vs. laser power functions were used as the melting criterion. The melting curve was corroborated with in situ X-ray diffraction experiments in both the LH-DAC and multi-anvil press in which the appearance of liquid diffuse scattering in the diffraction patterns was used as the melting criterion. At all pressures, the NiSi melting curve is lower than that of FeSi, with the difference in melting temperature reaching a maximum of 900 K at 14 GPa. The location of the B31 + B20 + L triple point has been constrained to 12 ± 2 GPa and 1550 ± 100 K and the B20 + B2 + L triple point to 28.5 ± 1.5 GPa and 2165 ± 60 K. On the basis of the in situ LH-DAC experiments the Clapeyron slope of the B20 → B2 transition is estimated at −67 MPa K−1. Extrapolation of the B2-NiSi liquidus to core-mantle boundary (CMB) conditions (135 GPa) suggests the melting point of NiSi (3700 ± 400 K) will be only marginally lower than that of isostructural FeSi (4000 ± 200 K). Thus any (Fe,Ni)Si solid solution present within the D″ layer is expected to remain solid, with the possible exception of the very hottest region adjacent to the CMB.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014, Elsevier. This is an author produced version of a paper published in Physics of the Earth and Planetary Interiors. Uploaded in accordance with the publisher's self-archiving policy. NOTICE: this is the author’s version of a work that was accepted for publication in Physics of the Earth and Planetary Interiors. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Physics of the Earth and Planetary Interiors, 223,(2014) DOI 10.1016/j.pepi.2014.05.005 |
Keywords: | NiSi; melting; high-pressure; in situ; LH-DAC |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 01 Jul 2014 14:55 |
Last Modified: | 29 Oct 2020 12:26 |
Published Version: | http://dx.doi.org/10.1016/j.pepi.2014.05.005 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.pepi.2014.05.005 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:79386 |