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

¹ Laboratoire de Sciences de la Terre, ENSL 46, allée d'Italie, 69364 Lyon cedex 07, France
² Geophysical Laboratory and Center for High Pressure Research Carnegie Institution of Washington - 5251 Broad Branch Road NW Washington DC 20015, USA
³ Laboratoire de Minéralogie-Cristallographie, IPGP 4, place Jussieu, 75252 Paris cedex 05, France
⁴ ESRF, Experiments Division - B.P. 220, 38043 Grenoble cedex, France
⁵ Laboratoire des Isotopes Stables, IPGP - Paris, France

Received: 13 June 2000
Accepted: 31 August 2000

Abstract

High-energy synchrotron X-ray diffraction measurements on liquid iron in the vicinity of the δ-γ-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.