Scanning Tunneling Microscopy Study of a Vicinal Anatase TiO₂ Surface

Using scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED), the structure of the anatase TiO 2 (51̅4) surface, ∼10° vicinal to the lowest-energy (101) plane, has been studied. The surface was found to facet into a structure composed of ridges with a uniform width of five lattice units. On the basis of atomically resolved STM and electron counting rules, it is proposed that the sides of the ridges are parallel to (11̅0) and (112) planes. These sides might be reconstructed to stabilize the microfaceted structure. Vapor-deposited gold shows pronounced clustering between the ridges, indicating a one-dimensional template effect of the vicinal surface, which supports denser and more uniformly sized Au clusters, as compared to the flat (101) surface.