X-ray study of iron with in-situ heating at ultra high pressures

We provide experimental evidence concerning the structure and the pressure-temperature stability of a new polymorph of iron with the double hexagonal close-packed (DHCP) structure. This experiment was performed by an in-situ electrical heating of an iron-wire at argon pressures of 31 and 48 GPa. The results demonstrate the stability of the new phase and the reversibility of the transformation of iron between the hexagonal close-packed (HCP) and DHCP structures at high pressure and temperature corresponding to a depth of over 1500 km in the Earth's interior.