Dresden 2014 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 17: Modeling and Data Analysis

DY 17.4: Vortrag

Mittwoch, 2. April 2014, 10:15–10:30, ZEU 146

Spin crossover in liquid (Mg,Fe)O from first-principles simulations — •Eero Holmstrom and Lars Stixrude — Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK

When a planet is formed through accretion, it is likely that substantial or complete melting of the body occurs. Understanding the molten state of planetary materials is important, because their solidification sets the initial conditions for the creation and evolution of the lithosphere and atmosphere of planets like the Earth. Using density-functional theory molecular dynamics simulations in conjunction with thermodynamic integration, we model liquid (Mg,Fe)O, the molten phase of the abundant Earth material ferropericlase, at high pressures and temperatures. Firstly, we present a phase diagram of the spin crossover of the Fe ions from a high-spin to a low-spin state with increasing pressure, and predict the equation of state of the melt. Secondly, we compute the electrical conductivity of the liquid. Finally, we assess the implications of our results for the early Earth and other planets.