Publication Date:
2019-04-01
Description:
The elasticity of hcp-Fe-5wt%Si has been investigated by synchrotron X-ray diffraction up to 110 GPa and 2,100 K and by picosecond acoustics measurements at ambient temperature up to 115 GPa. The established Pressure-Volume-Temperature equation of state shows that the density of the Earth's inner core can be matched by an Fe-Si alloy with 5wt% Si for all reasonable core temperatures, but that its compressional and shear velocities remain too high with respect to seismological observations. On the other hand, Fe-Si alloys whose velocities are expected to get close to seismological observations are too dense at relevant temperatures. Thus, based on these combined velocity-density measurements, silicon is not likely to be the sole light element in the inner core.
Print ISSN:
2169-9313
Electronic ISSN:
2169-9356
Topics:
Geosciences
,
Physics
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