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.