Structural changes in liquid Fe at high pressures and high temperatures from Synchrotron X-ray Diffraction

Abstract

High-energy synchrotron X-ray diffraction measurements on liquid iron in the vicinity of the delta-gamma -liquid triple point (to 2300 K and 5 GPa) reveal significant changes in the structure of the liquid upon increasing pressure and temperature. The second and third neighbor shells in the g(r) shift to shorter distances and develop new structure with increasing pressure. The results can be interpreted in terms of the liquid acquiring bcc-like local order which evolves to a mixture of bcc- and fcc-like local order as pressure and/or temperature are raised.