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

• DOI: 10.1016/j.susc.2012.07.024
• Publication Date: 2012-07-29T21:33:41Z
• Authors: R. Verre; R.G.S. Sofin; V. Usov; K. Fleischer; D. Fox; G. Behan; H. Zhang; I.V. Shvets
• Keywords: Faceting; Vicinal; Template; Surface reconstruction; Terrace (agriculture)

We report on a heat-induced transformation of the surface of α-alumina (0001) crystals which have an off-cut in the [12¯10] direction. Annealing the crystal causes the surface to transform into a regular array of (0001) and (12¯16) facets. The resultant faceted morphology represents the equilibrium state of the system. It is demonstrated that the average terrace periodicity is determined by the annealing temperature. Possible causes for the surface rearrangement are also discussed. This method could be used for producing templates with controlled periodicity for growth of nanostructure arrays.