Studies of single crystal TiO₂ (001) and (100) surfaces by reflection high energy electron diffraction and reflection electron microscopy

Reflection electron microscopy combined with reflection high energy electron diffraction has been used to investigate rutile (001) and (100) surfaces which are annealed in an oxygen atmosphere at 1425°C for 36 h. The stereoscopic observations on rutile surface structures have been accomplished by imaging at different azimuthal directions satisfying surface resonance conditions. The (001) surface is shown to be faceted on {214} planes. Large areas of flat terraces 0.5-1.0 microm wide and big steps 20-30 nm high are the main features observed on the rutile (100) surface. Strain fields near big step edges are responsible for the streaks observed in REM images. The slip traces observed on the (100) surface are along the [010] direction, which are consistent with the slip system {011} 〈01̄1〉 of non-reduced bulk crystal. Contamination particles, acting as pinning sites along big steps, have significant influences on the surface morphology.