title: Melting of iron determined by X-ray absorption spectroscopy to 100 GPa.
abstract: Temperature, thermal history, and dynamics of Earth rely critically on the knowledge of the melting temperature of iron at the pressure conditions of the inner core boundary (ICB) where the geotherm crosses the melting curve. The literature on this subject is overwhelming, and no consensus has been reached, with a very large disagreement of the order of 2,000 K for the ICB temperature. Here we report new data on the melting temperature of iron in a laser-heated diamond anvil cell to 103 GPa obtained by X-ray absorption spectroscopy, a technique rarely used at such conditions. The modifications of the onset of the absorption spectra are used as a reliable melting criterion regardless of the solid phase from which the solid to liquid transition takes place. Our results show a melting temperature of iron in agreement with most previous studies up to 100 GPa, namely of 3,090 K at 103 GPa.
authors.affiliation: Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy; giuliana.aquilanti@elettra.eu.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Aquilanti
authors.affiliation: Operative Group Grenoble (OGG)-Istituto Officina dei Materiali-Consiglio Nazionale delle Ricerche (CNR), 38043 Grenoble Cedex 9, France;
authors.forename: Angela
authors.initials: A
authors.lastname: Trapananti
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015; Geowissenschaften, Goethe-Universität, D-60438 Frankfurt a.M., Germany;
authors.forename: Amol
authors.initials: A
authors.lastname: Karandikar
authors.affiliation: European Synchrotron Radiation Facility, 38043 Grenoble Cedex 9, France.
authors.forename: Innokenty
authors.initials: I
authors.lastname: Kantor
authors.affiliation: European Synchrotron Radiation Facility, 38043 Grenoble Cedex 9, France.
authors.forename: Carlo
authors.initials: C
authors.lastname: Marini
authors.affiliation: European Synchrotron Radiation Facility, 38043 Grenoble Cedex 9, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Mathon
authors.affiliation: European Synchrotron Radiation Facility, 38043 Grenoble Cedex 9, France.
authors.forename: Sakura
authors.initials: S
authors.lastname: Pascarelli
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015;
authors.forename: Reinhard
authors.initials: R
authors.lastname: Boehler
keywords: XAS; iron melting curve; megabar range