Noncontact-mode atomic force microscopy observation of alpha-Al2O3(0001) surface

Single-crystalline alpha-Al2O3(0001) surfaces were investigated by low-ener gy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and noncontact-mode atomic force microscopy (NC-AFM).When the alpha-Al2O3(0001) surface was annealed in air at 1273 K, terraces of similar to 80 nm width and steps of similar to 0.2 nm height appeared. NC-AFM topography revealed, however, that the terraces were not atomically flat. Several previously re ported methods for preparing (1 x 1) alpha-Al2O3(0001) surfaces were examin ed. However, the cleaning procedures used in these methods were not suffici ent to prepare atomically flat (1 x 1) alpha-Al2O3(0001) surfaces; the surf aces thus prepared exhibited a topography which was much more ragged than t hat of an as-received surface.