High-temperature electrical resistivity measurements of hcp iron to Mbar pressure in an internally resistive heated diamond anvil cell

ABSTRACT

Electrical and thermal transport properties of iron are of great importance for understanding the thermal evolution and dynamics of the Earth’s core, of which iron is a major component. However, the reported values of iron’s conductivity at core conditions are still highly controversial. In this study, we employed an internally resistive heated diamond anvil cell (IHDAC) technique that reduces temperature heterogeneity inside the heated sample, and revisited the electrical resistivity of hexagonal closed packed (hcp) iron up to 110 GPa and 2500 K. Our results are in complete agreement with the reported values of the high pressure-temperature electrical resistivity of hcp iron obtained by using the laser-heated diamond anvil cell technique, supporting high iron conductivity at the Earth’s core conditions. The high pressure-temperature resistivity measurement in an IHDAC employed here would be a more suitable method to examine more resistive iron alloys at the Earth’s core conditions.

KEYWORDS:

• Electrical resistivity
• Earth’s core
• hcp iron
• thermal conductivity
• internally heated diamond anvil cell

Acknowledgments

The synchrotron X-ray diffraction experiments were performed at the BL10XU of SPring-8 (Proposal No. 2017B1730, 2018A0072).

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Sho Suehiro http://orcid.org/0000-0003-3063-5050

Additional information

Funding

This work was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI [grant number 26707029, 15H05827, and 17H04861].