Atomically Resolved Silver Imaging on theSi(111)−(3×3)−AgSurface Using a Noncontact Atomic Force Microscope

We experimentally investigate the noncontact atomic force microscopy (AFM) imaging on the $\mathrm{Si}\left(111\right)-(\sqrt{3}\times \sqrt{3})-\mathrm{Ag}$ surface. An individual silver atom on the topmost layer of the surface can be resolved. The image patterns have no distance dependence, which suggests that the strong chemical-bonding interaction between the tip and the surface does not contribute to image contrast. The silver atom on the surface seems to be resolved with the silver adsorbed tip. This result suggests that the noncontact AFM images drastically change depending on the atom species (e.g., silver or silicon) on the tip apex.