Scanning tunnelling microscopic imaging of TiO2(110) with atomic-scale resolution was carried out. Sputtering and subsequent annealing under ultra-high vacuum at 600 to 900K resulted in the (110)-(1 x 1) terraces bounded by steps parallel to the [1¯11] or [001] direction. Five-fold coordinated Ti4+ cations ordered in (1 x 1) periodicity were resolved on the terraces. Further annealing at 900 to 1100K formed strings composed of double ridges along the [001] direction on the (110)-(1 x 1) terraces. The strings covered the surface to give a (1 x 2) superstructure when annealed at 1150K. low-energy electron diffraction patterns consistent with the transformations were observed.

Reconstruction of TiO2(110) Surface - STM Study with Atomic-Scale Resolution. Onishi, H., Iwasawa, Y.: Surface Science, 1994, 313[1-2], L783-9