Thermal conductivity of platinum and periclase under extreme conditions of pressure and temperature

ABSTRACT

We have measured the thermal diffusivity and conductivity of platinum and MgO periclase at high pressures (P) and high temperatures (T) by combining the pulsed light heating thermoreflectance technique with a laser-heated diamond anvil cell. The obtained thermal conductivity of platinum shows positive pressure and temperature dependences, reaching about 210 W/m/K at the highest P–T condition of 125 GPa and 1850 K. The thermal conductivity of periclase was determined up to 140 GPa and 1950 K, corresponding to the Earth's lowermost mantle, where the conductivity was about 90 W/m/K. Our measurements allow us to test models for the combined P–T dependence of the thermal conductivity of both metals and insulating materials up to Mbar pressures and thousands of kelvins.

KEYWORDS:

• Thermal conductivity
• platinum
• periclase
• high pressure
• thermoreflectance

Acknowledgments

We thank two anonymous reviewers for their constructive comments that improved the quality of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by JSPS KAKENHI [Grant Nos. 20J13665, 19H00716, and 19H01995]; Ministry of Education, Culture, Sports, Science and Technology.