Thermal conductivity of argon at high pressures and high temperatures

Abstract

Knowledge of the thermal conductivity of Ar under conditions of high pressures and temperatures (P-T) is important for model calculations of heat transfer in the laser heated diamond anvil cell (DAC) as it is commonly used as a pressure transmitting medium and for thermal insulation. We used a modified transient heating technique utilizing microsecond laser pulses in a symmetric DAC to determine the P-T dependent thermal conductivity of solid Ar up to 50 GPa and 2500 K. The temperature dependent thermal conductivity of Ar was obtained by fitting the results of finite element calculations to the experimentally determined time dependent temperature of a thin Ir foil surrounded by Ar. Our data for the thermal conductivity of Ar are larger than that theoretically calculated using the Green-Kubo formalism, but they agree well with those based on kinetic theory. These results are important for ongoing studies of the thermal transport properties of minerals at pressures and temperatures native to the mantle and core.

Opacity and conductivity measurements in noble gases at conditions of planetary and stellar interiors

“…Here we report experiments in the laser-heated diamond anvil cell (15,16,(26)(27)(28)(29) on high-density and high-temperature states of the noble gases Xe, Ar, Ne, and He ( Fig. 1).…”

“…1). Rapid heating and cooling of compressed samples using pulsed laser heating (26,27) is coupled with time domain spectroscopy of thermal emission (26) to determine sample temperature and transient absorption to establish corresponding sample optical properties (Figs. S1 and S2).…”

Portable double-sided pulsed laser heating system for time-resolved geoscience and materials science applications

“…An entirely new field of research has been introduced, allowing determination of important material properties such as thermal conductivity and diffusivity and melting temperatures. [15][16][17][18] The spatial distribution of temperatures at and around the heated spot is of great importance in a LHDAC experiment. The significance of a surface temperature map has been noted in many studies.…”

Origins of thermal conductivity changes in strained crystals

“…They predicted the same power-law scaling from Fermi's golden rule (exponent within 5%) based on analytical scalings of the phonon lifetime and sound speed. Goncharov et al experimentally investigated thermal transport in high-temperature, compressed argon using a transient heating technique [17]. Using a diamond anvil cell, argon was compressed in the stress range of 10 to 50 GPa.…”