Imaging Patterns Of Anatase Tio2(001) With Non-Contact Atomic Force Microscopy

Image patterns of anatase TiO2(001) with non-contact atomic force microscopy (NC-AFM) are presented. A combined system of NC-AFM with pulsed laser deposition, scanning tunneling microscopy (STM), and low energy electron diffraction (LEED) enables us to prepare clean surfaces of anatase TiO(2 )thin films and to perform measurements on them without breaking the vacuum or the need of cleaning the surface with sputtering and annealing cycles. Results from STM and LEED show that the anatase TiO2(001) films display a (1 x 4) surface pattern of row structures. At far distances, in which the frequency shift was relatively small, NC-AFM images show three different patterns (labeled as protrusion, hole, and neutral contrast, respectively) similar to the ones that have been reported before in the studies of the rutile TiO2 surface. At closer tip-sample distances, a periodic pattern consistent with the TiO2 lattice constant was observed along the higher-positioned TiO3 rows. We have also observed that energy dissipation is induced only with platinum tips, and not with other tip apexes.