6533b871fe1ef96bd12d1855
RESEARCH PRODUCT
Isothermal equation of state and phase stability of Fe 5 Si 3 up to 96 GPa and 3000 K
A. R. MakhlufAbby KavnerDavid Santamaría-pérezDavid Santamaría-pérezC. P. Mcguiresubject
DiffractionEquation of stateWork (thermodynamics)Bulk modulusMaterials science010504 meteorology & atmospheric sciencesNoble gasThermodynamics010502 geochemistry & geophysics01 natural sciencesDiamond anvil cellIsothermal processGeophysicsSpace and Planetary ScienceGeochemistry and PetrologyThermalEarth and Planetary Sciences (miscellaneous)0105 earth and related environmental sciencesdescription
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 cm3mol-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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-06-01 | Journal of Geophysical Research: Solid Earth |