Viscosity of liquid iron derived from the liquid structure data at high pressures
Abstract
Whether viscosity of liquid iron increases moderately or rather considerably with pressure is a subject of extensive studies by various models of theory and, recently, by experimental measurements at pressures up to 20 GPa. In this presentation, we report the result of viscosity of liquid iron to 58 GPa calculated by employing the mode-coupling theory and based on experimental results of structure factors of liquid iron at high pressures. The recent version of mode-coupling theory [1], where only the coupling between density fluctuations contributes to viscosity, has been proven as a suitable description of dynamics in simple liquid metals on atomic length scales. As input for the calculations, only the experimental structure factor and the density at a given pressure are required. Along (and slightly above) the melting curve, the structure of liquid iron are experimentally determined to 58 GPa [2], which displays hard-sphere-like behavior. The mode-coupling calculation from the experimental data shows that the viscosity values at high pressures are slightly larger than that at ambient conditions, but within the same order of magnitude. Our results are in reasonable agreements with recent experimental results at relatively low pressures and those from molecular dynamics calculations. [1] W. Schirmacher et al. in preparation; W. Goetze and M. Luecke, Phys. Rev. A 13, 3822 (1976). [2] G. Shen, V. Prakapenka, M. Rivers, S. Sutton, Phys. Rev. Lett., 92, 185701, (2004)
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFMMR53B0988S
- Keywords:
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- 1212 Earth's interior: composition and state (7207;
- 7208;
- 8105;
- 8124);
- 1213 Earth's interior: dynamics (1507;
- 7207;
- 7208;
- 8115;
- 8120);
- 3600 MINERALOGY AND PETROLOGY;
- 3900 MINERAL PHYSICS