Regensburg 2013 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 25: Critical Phenomena and Phase Transitions

DY 25.1: Vortrag

Donnerstag, 14. März 2013, 09:30–09:45, H46

Computing melting temperatures of Na, Mg, Al and Si by pinning of solid-liquid interfaces in ab-initio calculations — •Felix Hummel¹, Ulf R. Pedersen^1,2, Georg Kresse¹, Gerhard Kahl², and Christoph Dellago¹ — ¹Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria — ²Institute of Theoretical Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, A-1040 Vienna, Austria

We use a novel approach for computing the Gibbs free energy difference between phases of a material. The force acting on an interface separating two phases of interest is determined by applying an external field biasing two-phase configurations. This force is proportional to the Gibbs free energy difference between the phases.

We demonstrate the accuracy, efficiency and practical applicability of this approach by computing the melting temperature at ambient pressure of Na, Mg, Al and Si using ab-initio calculations with VASP. Whereas predicted melting temperatures are in good agreement with experiment for Na, Mg and Al, the melting temperature of Si is underestimated, in agreement with previous computations.