Physical properties of liquid Fe alloys at high pressure and their bearings on the nature of metallic planetary cores

[1] Sulfur and silicon are among the expected alloying light elements in planetary liquid iron cores. Structural properties of Fe-27 wt % S and Fe-17 wt % Si liquid alloys at high pressure and high temperature (0-5 GPa/1400-2300 K) are measured by synchrotron X-ray diffraction. Sulfur strongly modifies the local structure of liquid iron whereas silicon has only small structural effects. Fe-27 wt % S melts are indeed poorly ordered which explains a higher compressibility compared to pure liquid Fe. These results point out the necessity to consider the strong effect of S on liquid Fe properties while modeling planetary interiors. They imply a low S content in the Earth's outer core, leaving Si as a strong candidate, and argue for a present-day Martian solid core when combined with previous global chemical models.


Published in:
Journal Of Geophysical Research-Solid Earth, 107, -
Year:
2002
Keywords:
Laboratories:




 Record created 2011-09-29, last modified 2018-03-17

n/a:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)