Imaging the TiO2(011)-(2 × 1) Surface using Noncontact Atomic Force Microscopy and Scanning Tunneling Microscopy

Abstract

We have used noncontact atomic force microscopy (NC-AFM) and scanning tunneling microscopy (STM) to study the rutile TiO2(011)-(2 × 1) surface. NC-AFM images were obtained with several different contrasts. In particular, a zigzag contrast similar to that found in STM was observed. Simultaneously recorded NC-AFM and STM images indicate that the zigzags in NC-AFM and STM are in phase and may therefore have a similar origin. Hydrogen adatoms were also identified in NC-AFM images by comparison with STM. Sequential NC-AFM scans of the same area show that these hydrogen atoms readily diffuse between adjacent topmost oxygen atoms and follow a zigzag path, thus indicating that the H adatoms adsorb on either side of the (2 × 1) rows.