Berlin 2015 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 17: Postersession I
MM 17.26: Poster
Montag, 16. März 2015, 18:00–20:00, Poster E
Phase equilibria and interfacial properties of a curved liquid-solid interface — •Muhammad Ajmal Choudhary1, Julia Kundin1, Martin Oettel2, and Heike Emmerich1 — 1Lehrstuhl für Material- und Prozesssimulation, Universität Bayreuth, D-95440 Bayreuth — 2Institut für Angewandte Physik, Universität Tübingen, D-72076 Tübingen
The phase field crystal (PFC) technique is a novel approach for modeling crystal growth phenomena with atomistic resolution on mesoscopic time scales. We use a 2D PFC model for a binary system based on Elder et al. [Phy. Rev. B 75, 064107 (2007)] to establish a precise assessment of the nucleation mechanisms beyond classical nucleation theory. More specifically, we investigate the equilibrium properties of a curved liquid-solid interface as well as the nucleation barriers. We propose the method of determining interfacial energies for a curved liquid-solid interface in a finite system by stabilizing the circular solid crystal of various radii in the surrounding liquid phase and liquid droplets of various radii in the corresponding solid phase. We suggest a phenomenological expression to describe the dependence of the extracted interface tension on the nucleus radius r for the liquid-solid system. The numerical PFC results show that this dependency can not be fully described by the non-classical Tolman formula. Moreover, we also derived the free energy barriers for the nucleation and compared the results with predictions based on classical nucleation theory.