Equilibrium faceting formation in vicinal Al2O3 (0001) surface caused by annealing

► Annealing of Al2O3 (0001) at a high temperature produces a faceted surface. ► The final morphology of the system can be tuned by changing the annealing parameters. ► From TEM analysis the facet orientations are obtained. ► Possible mechanisms for the origin of the faceted morphology are discussed.