A new Measurement of Thermal Conductivity of Iron at high pressures and temperatures

Abstract

Thermal conductivity of the most abundant element in the planetary core, Iron (Fe) is measured up to Earth's outer core pressure $\sim 120$ GPa. The measurements are carried out using the laser heated diamond anvil cell facility, where the absorbed power by Fe metal foil is calculated using thermodynamical equation. The thermal conductivity of $\gamma-Fe$ linearly increases up to a maximum experimental pressure 40 GPa. Thermal conductivity of $\epsilon-Fe$ measured by us shows a saturated value $\sim$ 52 ($\pm$ 5) $Wm^{-1}K^{-1}$ in the pressure range 77 - 120 GPa. At different pressures temperature dependence of thermal conductivity show a sharp drop during melting, which indicates the formation of liquid layer resulting in a thermal buffer to the heat conduction.