Nanotubes and force interactions in an atomic force microscope

The conditions for nanotubes to be used as atomic force microscope (AFM) probes are analyzed. It is shown theoretically for the first time that single-and multilayer tubes with diameters ranging from 0.5 to 5 nm give atomic-level resolution of the surface. The presence of cylindrical symmetry makes each surface atom of a nanotube “imaging.” For a definite ratio of the diameter of a single nanotube and the period of the surface structure, the atomic resolution vanishes. Such nanotubes are of special interest for probing the details of the large-scale relief and for investigations in nanotribology. In contrast to silicon and other (solid) probes, nanotubes are not blunted on contact with the surface, but rather they bend and their initial shape is restored when the stress is removed. The critical loads for an AFM to function in the repulsive regime are determined.