Earth’s inner core is predominantly composed of solid iron (Fe) and displays intriguing properties such as strong shear softening and an ultrahigh Poisson’s ratio. Insofar, physical mechanisms to explain these features coherently remain highly debated. Here, we have studied longitudinal and shear wave velocities of hcp-Fe (hexagonal close-packed iron) at relevant pressure–temperature conditions of the inner core using in situ shock experiments and machine learning molecular dynamics (MLMD) simulations. Our results demonstrate that the shear wave velocity of hcp-Fe along the Hugoniot in the premelting condition, defined as
We conducted shock wave experiments on iron carbide Fe3C up to a Hugoniot pressure of 245 GPa. The correlation between the particle velocity (
- Award ID(s):
- 1619868
- NSF-PAR ID:
- 10446330
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 46
- Issue:
- 20
- ISSN:
- 0094-8276
- Page Range / eLocation ID:
- p. 11018-11024
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Knowledge of the sound velocity of core materials is essential to explain the observed anomalously low shear wave velocity (
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