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Title: Partial melting in the iron-sulfur system at high pressure: A synchrotron X-ray diffraction study

Abstract

Partial melting in the Fe-S system was investigated at high pressures because of its importance to understanding the formation, composition, and thermal structure of the Earth's core. Earlier studies at very high pressure (>25 GPa) took place before the discovery of Fe{sub 3}, which compromised the interpretation of those results. Furthermore, they relied on textural criteria for melting that are difficult to apply at high pressure. In this study synchrotron X-ray diffraction was used to monitor coexisting metal and sulfide at high pressures and temperatures, during laser heating in a diamond anvil cell. The criterion for melting was the disappearance of one of the two coexisting phases, and reappearance upon quench. Temperatures of eutectic melting between Fe and Fe{sub 3}S were bracketed in this way up to 60 GPa, and a lower bound was established at 80 GPa. The accuracy of the melting point measured in these studies was improved through modelling of the axial temperature distribution through the thickness of the sample; this indicated an {approx}6% correction to the spectroradiometrically determined temperature. The Fe-Fe{sub 3}S eutectic composition remains close to 15 wt% S up to 60 GPa.

Authors:
; ; ; ;  [1]
  1. Maryland
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE
OSTI Identifier:
1007587
Resource Type:
Journal Article
Journal Name:
Physics of the Earth and Planetary Interiors
Additional Journal Information:
Journal Volume: 162; Journal Issue: (1-2) ; 06, 2007; Journal ID: ISSN 0031-9201
Country of Publication:
United States
Language:
ENGLISH
Subject:
43 PARTICLE ACCELERATORS; ACCURACY; DIAMONDS; EUTECTICS; HEATING; LASERS; MELTING; MELTING POINTS; MONITORS; SULFIDES; SYNCHROTRONS; TEMPERATURE DISTRIBUTION; THICKNESS; X-RAY DIFFRACTION

Citation Formats

Campbell, A J, Seagle, C T, Heinz, D L, Shen, G, Prakapenka, V, CIW), and UC). Partial melting in the iron-sulfur system at high pressure: A synchrotron X-ray diffraction study. United States: N. p., 2008. Web. doi:10.1016/j.pepi.2007.04.001.
Campbell, A J, Seagle, C T, Heinz, D L, Shen, G, Prakapenka, V, CIW), & UC). Partial melting in the iron-sulfur system at high pressure: A synchrotron X-ray diffraction study. United States. https://doi.org/10.1016/j.pepi.2007.04.001
Campbell, A J, Seagle, C T, Heinz, D L, Shen, G, Prakapenka, V, CIW), and UC). 2008. "Partial melting in the iron-sulfur system at high pressure: A synchrotron X-ray diffraction study". United States. https://doi.org/10.1016/j.pepi.2007.04.001.
@article{osti_1007587,
title = {Partial melting in the iron-sulfur system at high pressure: A synchrotron X-ray diffraction study},
author = {Campbell, A J and Seagle, C T and Heinz, D L and Shen, G and Prakapenka, V and CIW) and UC)},
abstractNote = {Partial melting in the Fe-S system was investigated at high pressures because of its importance to understanding the formation, composition, and thermal structure of the Earth's core. Earlier studies at very high pressure (>25 GPa) took place before the discovery of Fe{sub 3}, which compromised the interpretation of those results. Furthermore, they relied on textural criteria for melting that are difficult to apply at high pressure. In this study synchrotron X-ray diffraction was used to monitor coexisting metal and sulfide at high pressures and temperatures, during laser heating in a diamond anvil cell. The criterion for melting was the disappearance of one of the two coexisting phases, and reappearance upon quench. Temperatures of eutectic melting between Fe and Fe{sub 3}S were bracketed in this way up to 60 GPa, and a lower bound was established at 80 GPa. The accuracy of the melting point measured in these studies was improved through modelling of the axial temperature distribution through the thickness of the sample; this indicated an {approx}6% correction to the spectroradiometrically determined temperature. The Fe-Fe{sub 3}S eutectic composition remains close to 15 wt% S up to 60 GPa.},
doi = {10.1016/j.pepi.2007.04.001},
url = {https://www.osti.gov/biblio/1007587}, journal = {Physics of the Earth and Planetary Interiors},
issn = {0031-9201},
number = (1-2) ; 06, 2007,
volume = 162,
place = {United States},
year = {Thu Sep 18 00:00:00 EDT 2008},
month = {Thu Sep 18 00:00:00 EDT 2008}
}