From surface instabilities to nanostructures: numerical investigations

• Applicant: Professor Dr. Axel Voigt, since 11/2008
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: from 2008 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 98895065

In this project, we are interested in surface instabilities in epitaxial growth of metals and semiconductors. A detailed understanding of these instabilities offers the chance to control self assembling of nanostructures. In order to account for the multiscale nature of this problem, which relates the instability having its origin at the atomistic scale, to the array of nanostructures, we consider diffuse-interface approximations of the so-called Burton-Cabrera-Frank (BCF)-model [3], which resolves atomic distances in the growth direction but is coarse grained in the lateral directions. This leads to a higher order partial differential equation of Cahn-Hilliard type, which we can solve using our adaptive nite element software AMDiS [17]. From the modelling perspective, we will generalize the model proposed in [11] to account for anisotropies in kinetic coecients, surface free energy and mobilities to make a quantitative comparison with experiment possible.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr. Andreas Rätz, until 11/2008