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Title: Isothermal equation of state and phase stability of Fe 5Si 3 up to 96 GPa and 3000 K

Abstract

Here, the composition of Earth's core has first–order implications for understanding the thermal and chemical history of the deep Earth. The present work measures the pressure–volume equation of state of Fe 5Si 3 to 96 GPa in a diamond anvil cell using noble gas pressure media and demonstrates that Fe 5Si 3 is not stable at high temperature and pressure but reappears during thermal quench. The isothermal equation of state at ambient temperature of Fe 5Si 3 is given by the bulk modulus K T,0 = 167 (8) and K T,0' = 5.1 (2), with V 0 = 56.29 cm 3 mol –1. At high temperatures and pressures we observed the disappearance of hexagonal Fe 5Si 3 diffraction peaks and the appearance of peaks corresponding to cubic FeSi and Fe 3Si structures at 18 GPa and at the lowest measurable temperature (~1300 K), indicating that Fe 5Si 3 is not stable at high temperature. Upon temperature quench diffraction peaks corresponding to Fe 5Si 3 reappear, confirming its stability at ambient temperature and high pressure.

Authors:
ORCiD logo [1];  [2];  [1]; ORCiD logo [1]
  1. Univ. of California, Los Angeles, CA (United States)
  2. Univ. of California, Los Angeles, CA (United States); Univ. de Valencia, Valencia (Spain)
Publication Date:
Research Org.:
Univ of Chicago, Chicago, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
OSTI Identifier:
1474279
Grant/Contract Number:  
FG02-94ER14466
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Solid Earth
Additional Journal Information:
Journal Volume: 122; Journal Issue: 6; Journal ID: ISSN 2169-9313
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; xifengite; iron silicide; high‐pressure equation of state; diamond anvil cell; laser heating

Citation Formats

McGuire, C., Santamaria-Pérez, D., Makhluf, A., and Kavner, A. Isothermal equation of state and phase stability of Fe5Si3 up to 96 GPa and 3000 K. United States: N. p., 2017. Web. doi:10.1002/2017JB014136.
McGuire, C., Santamaria-Pérez, D., Makhluf, A., & Kavner, A. Isothermal equation of state and phase stability of Fe5Si3 up to 96 GPa and 3000 K. United States. doi:10.1002/2017JB014136.
McGuire, C., Santamaria-Pérez, D., Makhluf, A., and Kavner, A. Mon . "Isothermal equation of state and phase stability of Fe5Si3 up to 96 GPa and 3000 K". United States. doi:10.1002/2017JB014136. https://www.osti.gov/servlets/purl/1474279.
@article{osti_1474279,
title = {Isothermal equation of state and phase stability of Fe5Si3 up to 96 GPa and 3000 K},
author = {McGuire, C. and Santamaria-Pérez, D. and Makhluf, A. and Kavner, A.},
abstractNote = {Here, the composition of Earth's core has first–order implications for understanding the thermal and chemical history of the deep Earth. The present work measures the pressure–volume equation of state of Fe5Si3 to 96 GPa in a diamond anvil cell using noble gas pressure media and demonstrates that Fe5Si3 is not stable at high temperature and pressure but reappears during thermal quench. The isothermal equation of state at ambient temperature of Fe5Si3 is given by the bulk modulus KT,0 = 167 (8) and KT,0' = 5.1 (2), with V0 = 56.29 cm 3 mol–1. At high temperatures and pressures we observed the disappearance of hexagonal Fe5Si3 diffraction peaks and the appearance of peaks corresponding to cubic FeSi and Fe3Si structures at 18 GPa and at the lowest measurable temperature (~1300 K), indicating that Fe5Si3 is not stable at high temperature. Upon temperature quench diffraction peaks corresponding to Fe5Si3 reappear, confirming its stability at ambient temperature and high pressure.},
doi = {10.1002/2017JB014136},
journal = {Journal of Geophysical Research. Solid Earth},
number = 6,
volume = 122,
place = {United States},
year = {2017},
month = {5}
}

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Works referenced in this record:

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