Atom-resolved images of a ${\mathrm{TiO}}_2\left(110\right)-(1\times 1)$ surface were obtained by noncontact atomic force microscopy (NC-AFM) in ultrahigh vacuum. In contrast to previous scanning tunneling microscopy studies, outermost atoms of bridge-bound oxygen ridges were observed as protruding rows by NC-AFM. A high-resolution image of the surface revealed that the bridging oxygen atoms ordered in $(1\times 1)$ periodicity on terraces. Point defects of oxygen atoms were also imaged as dark spots.

• Received 7 July 1997

DOI:https://doi.org/10.1103/PhysRevLett.79.4202