Effect of magnesium oxide on faceted vicinal (0001) surface of aluminum oxide

Abstract

Atomic force microscopy has been used to observe the vicinal (0001) surface of Al2O3. The surface develops a hill-and-valley structure when heat-treated in air and becomes defaceted and therefore atomically rough when heat-treated in an MgO atmosphere at 1600 degreesC. The results are consistent with the previously observed polyhedral equilibrium shape of Al2O3 crystal and the surface roughening effect of MgO.