Abstract. Electron bombardment from a filament as well as voltage pulses from a scanning tunnelling microscope tip have been employed to modify the surface of TiO₂(110). Individual H atoms are selectively desorbed with electrical pulses of +3 V from the scanning tunnelling microscope tip, whilst leaving the oxygen vacancies intact. This allows us to distinguish between oxygen vacancies and hydroxyl groups, which have a similar appearance in scanning tunnelling microscopy images. This then allows the oxygen vacancy-promoted dissociation of water and O₂ to be followed with the microscope. Electrical pulses between +5 and +10 V induce local TiO₂(110)1 × 2 reconstructions centred around the pulse. As for electron bombardment of the surface, relatively low fluxes increase the density of oxygen vacancies whilst higher fluxes lead to the 1 × 2 and other 1 × n reconstructions.

Print publication: Issue 21 (14 November 2006)
Received 12 July 2006, in final form 15 September 2006
Published 13 October 2006