Simulation of crack propagation in alumina with ab initio based polarizable force field

Abstract

We present an effective atomic interaction potential for crystalline α-Al2O3 generated by the program potfit. The Wolf direct, pairwise summation method with spherical truncation is used for electrostatic interactions. The polarizability of oxygen atoms is included by use of the Tangney-Scandolo interatomic force field approach. The potential is optimized to reproduce the forces, energies, and stresses in relaxed and strained configurations as well as {0001}, $\lbrace 10\overline{1}0\rbrace${101¯0}, and $\lbrace 11\overline{2}0\rbrace${112¯0} surfaces of Al2O3. Details of the force field generation are given, and its validation is demonstrated. We apply the developed potential to investigate crack propagation in α-Al2O3 single crystals.