Atomistic lattice simulations were used to calculate the energies of stacking faults in the Al sub-lattice of the a phase. Three potentials were used. The first 2 were derived by first ascribing formal charges to Al and O (3+ and 2-, respectively), and then using 2 different methods to determine a short-range 2-body interaction. The third was deduced from ab initio Hartree-Fock calculations. It was found that stacking faults on the (00•1) planes, with a fault vector of 1/3<10•0>, were high in energy (1.2 to 4.6J/m2) and were sensitive to the potential model which was used. The energies of stacking faults on the {10•0} and {11•0} planes, with a fault vector of 1/3<10•0>, were lower in energy (0.3 to 0.9J/m2) and compared favorably with experimental data.

Calculated Stacking-Fault Energies in α-Al2O3. P.R.Kenway: Philosophical Magazine B, 1993, 68[2], 171-83