Dynamical properties of AlN nanostructures and heterogeneous interfaces predicted using COMB potentials

A new empirical variable charge potential has been developed for AlN within the third-generation charge optimized many-body (COMB3) potential framework. The potential is able to reproduce the fundamental physical properties of AlN, including cohesive energy, elastic constants, defect formation energies, surface energies and phonon properties of AlN obtained from experiments and first-principles calculations. The thermodynamic properties of the Al(1 1 1)-AlN (101¯0) and Al₂O₃(0 0 0 1)-AlN (101¯0) interfaces and the tensile response of AlN nanowires and nanotubes are investigated in classical molecular dynamical (MD) simulations using this COMB3 potential. The results demonstrate that the potential is well suited to model heterogeneous materials in the Al-O-N system. Most importantly, the fully transferrable potential parameters can be seamlessly coupled with existing COMB3 parameters of other elements to enable MD simulations for an even wider range of heterogeneous materials systems.