RECONSTRUCTION OF TIO2(110) SURFACE - STM STUDY WITH ATOMIC-SCALE RESOLUTION

We succeeded in STM imaging of TiO2(110) with atomic-scale resolution. Sputtering and subsequent annealing under UHV at 600-900 K resulted in the (110)-(1 x 1) terraces bounded by steps parallel to the [111BAR] or [001] direction. Five-fold coordinated Ti4+ cations ordered in (1 x 1) periodicity were resolved on the terraces. Further annealing at 900-1100 K 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 1150 K. LEED patterns consistent with the transformations were observed.