  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.
