EXTENDED DEFECTS ON TIO2(100)1X3

STM, scanning tunneling spectroscopy (STS) and LEED have been used to investigate the interaction of structural elements associated with rut ile TiO2(100)1 X 3. These include the O-vacancy-induced 1 X 3 reconstr uction and steps in the two principal azimuths. LEED data from a 2.6 d egrees vicinal sample show splitting of the primary and 1/3rd order be ams in the [010] direction and not the vicinal off-cut [001] direction . A simple spot-profile analysis reveals that the up-down steps formed have a height of 4.59 +/- 0.05 Angstrom and a periodicity of 45 +/- 1 0 Angstrom. The STM(S) results image the microfacet morphology of the 1 X 3 reconstruction suggested by diffraction measurements. They also provide an explanation for the stabilisation of up-down steps, which i nvolves maximising the area of the (110) microfacets.