Upon sputtering and annealing in ultra-high vacuum at about 1000K, the (110) rutile surface underwent a 1 x 1 → 1 x 2 phase transition. The resultant 1 x 2 surface was Ti-rich, and formed by strands of double Ti rows as seen in scanning tunneling microscopic images. However, its detailed structure and composition was the subject of great debate. Recently, it had been proposed (Park et al., 2006) that the Ti atoms were located on interstitial sites having Ti2O stoichiometry. This model, when analyzed using low-energy electron diffraction data, did not yield an agreement between theory and experiment which was as good as the previous best fit of the Onishi-Iwasawa model for long-range 1 x 2 reconstruction. Therefore, the Ti2O3 added row was the preferred one from the point of view of low-energy electron diffraction.

LEED-IV Study of the Rutile TiO2(110)-1x2 Surface with a Ti-Interstitial Added-Row Reconstruction. M.Blanco-Rey, J.Abad, C.Rogero, J.Méndez, M.F.López, E.Román, J.A.Martín-Gago, P.L.de Andrés: Physical Review B, 2007, 75[8], 081402 (4pp)