The Structure of Surface Steps on Low-Index Planes of Oxides.

Abstract
Surface steps have been observed on low-index planes of alpha-alumina and spinel. The steps were produced by annealing both bulk and perforated thin foil single crystals. A comparative study of bright-field TEM and dark-field REM of the same crystals makes it possible to construct models for the surface structure. Many faceted steps can be observed on the (0001), {0112}, {1010} and {1120} surfaces of alpha-alumina and on the {100} surface of spinel. A detailed study of step faceting and step facet movement during reheating is presented.