UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Thermodynamic stability of Fe/O solid solution at inner-core conditions

Alfè, A; Price, GD; Gillan, MJ; (2000) Thermodynamic stability of Fe/O solid solution at inner-core conditions. Geophysical Research Letters , 27 (16) 2417 - 2420. 10.1029/2000GL011567. Green open access

[img]
Preview
PDF
2000GL011567.pdf
Available under License : See the attached licence file.

Download (553kB)

Abstract

We present a new technique which allows the fully ab initio calculation of the chemical potential of a substitutional impurity in a high-temperature crystal, including harmonic and anharmonic lattice vibrations. The technique uses the combination of thermodynamic integration and reference models developed recently for the ab initio calculation of the free energy of liquids and anharmonic solids. We apply the technique to the case of the substitutional oxygen impurity in h.c.p. iron under Earth's core conditions, which earlier static ab initio calculations indicated to be thermodynamically very unstable. Our results show that entropic effects arising from the large Vibrational amplitude of the oxygen impurity give a major reduction of the oxygen chemical potential, so that oxygen dissolved in h.c.p. iron may be stabilised at concentrations up a few mol % under core conditions.

Type: Article
Title: Thermodynamic stability of Fe/O solid solution at inner-core conditions
Open access status: An open access version is available from UCL Discovery
DOI: 10.1029/2000GL011567
Publisher version: http://dx.doi.org/10.1029/2000GL011567
Language: English
Additional information: Copyright 2000 by the American Geophysical Union
Keywords: Generalized-gradient approximation, High-pressure, First-principles, Earths core, Energy calculations, Iron, Phase, Feo, Temperature
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy
UCL > Provost and Vice Provost Offices > VP Research
URI: https://discovery.ucl.ac.uk/id/eprint/99181
Downloads since deposit
114Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item