Molecular-dynamics computer simulation of crystal growth and melting in Al50Ni50A. Kerrache1, J. Horbach1, 2 and K. Binder1
1 Institut für Physik, Johannes Gutenberg-Universität Mainz - Staudinger Weg 7, 55099 Mainz, Germany
2 Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) 51170 Köln, Germany
received 11 December 2007; accepted in final form 4 January 2008; published March 2008
published online 6 February 2008
The melting and crystallization of Al50Ni50 are studied by means of molecular-dynamics computer simulations, using a potential of the embedded atom type to model the interactions between the particles. Systems in a slab geometry are simulated where the B2 phase of AlNi in the middle of an elongated simulation box is separated by two planar interfaces from the liquid phase, thereby considering the (100) crystal orientation. By determining the temperature dependence of the interface velocity, an accurate estimate of the melting temperature is provided. The value k = 0.0025 m/s/K for the kinetic growth coefficient is found. This value is about two orders of magnitude smaller than that found in recent simulation studies of one-component metals. The classical Wilson-Frenkel model is not able to describe the crystal growth kinetics on a quantitative level. We argue that this is due to the neglect of diffusion processes in the liquid-crystal interface.
81.10.Aj - Theory and models of crystal growth; physics of crystal growth, crystal morphology, and orientation.
64.70.D- - Solid-liquid transitions.
02.70.Ns - Molecular dynamics and particle methods.
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