ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Studying the kinetics of solid-liquid interfaces using transition path sampling

Date: 12.03.2013
Place: DPG Spring Meeting 2013, Regensburg, Germany

Daniel Sopu
Jutta Rogal
Ralf Drautz

The properties of solid-liquid interfaces such as interface energies, interface mobilities and their anisotropy, play an important role in solidification theory. In a first-order phase transformation these interfacial properties determine to a large extent nucleation barriers and growth rates. Depending on the height of the nucleation barrier and the applied driving force, the solidification process can take place on extended time scales which makes it very inefficient to be studied using regular molecular dynamics. Here, we use transition path sampling (TPS) to study the solid-liquid phase transformation in a Lennard-Jones system. TPS is a rare event technique that creates an ensemble of reaction trajectories between two metastable states in phase space. By re-weighting the path ensemble we extract thermodynamic and kinetic properties of the transition and explore the transition mechanisms. In particular we investigate interface free energies, the nucleation and formation of the solid-liquid interface, and anisotropic interface mobilities as a function of temperature.

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