Transitional structures of the TiO 110/ surface from p 1=1/ to 2 p 1=2/studied by impact collision ion scattering spectroscopy

The transitional states of surface structure of TiO2 110.from p 1=1.to p 1=2.on low reduced to heavily reduced surfaces were studied using Impact Collision Ion Scattering Spectroscopy ICISS.. We found that i.bridging oxygen rows were formed on low reduced surface at anneal temperature of 6508C for 2.5 h, ii. Ti2O unit rows were formed between the bridging oxygen rows on low reduced surface at anneal temperature of 9308C for 100 min, iii. five-fold titanium atom rows on the surface and titanium atom rows of the Ti2O rows are imperfectly covered with oxygen atoms on heavily reduced surface at anneal temperature of 6008C for 1 h and followed by 6708C annealing for 5 min after ion sputtering, and iv. Ti2O3 unit rows proposed by Onishi and IwasawawH. Onishi and Y. Iwasawa, Surf. Sci. Lett., 313, 1994, L783xwere completed by covering with oxygen atoms on all of the titanium atom rows on the Ti2O rows on heavily reduced surface at higher anneal temperature of 10508C for 40 min after ion sputtering. It is noticeable that the p 1=2.surface structures on low reduced surface is different from that of heavily reduced surface, viz., each has Ti2O unit rows and Ti2O3 unit rows, respectively. The result contradicts Amissing unit modelB proposed by Bennett et al. wR.A. Bennett, P. Stone, N.J. Price, M. Bowker, Phys. Rev. Lett., 82, 1999, 3831x. q2000 Elsevier Science B.V. All rights reserved.