Dresden 2014 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 33: Focus session: Resistive Switching by Redox and Phase Change Phenomena IV (Kinetic in oxides and phase change)

DS 33.6: Vortrag

Mittwoch, 2. April 2014, 18:00–18:15, CHE 89

Ab initio metadynamics simulation of phase change materials — •Ider Ronneberger, Wei Zhang, and Riccardo Mazzarello — Institute for Theoretical Solid State Physics, RWTH Aachen University

The microscopic description of the fast crystallization mechanism of phase change materials (PCMs) at elevated temperatures remains a challenge to both experimentalists and theorists. The computational limitation of ab initio Molecular Dynamics (AIMD) simulations in terms of system size and time scale can be partly overcome by the aid of enhanced sampling methods such as Metadynamics (MTD), which accelerates the exploration of the phase space and extracts estimations of the free energy changes involved in the process of interest. We study the crystallization of prototypical PCMs by means of AIMD and Well-Tempered MTD. MTD is used to enforce the formation of supercritical crystalline nuclei. The growth of the nuclei is subsequently investigated in unbiased AIMD runs.