It is demonstrated that a stepped (305) surface of a ${\mathrm{SrTiO}}_3$ crystal can be used routinely to evaluate the probing profile of scanning-force-microscopy probes. This provides a means to select optimal surface probes, and to evaluate possible image distortions within the range of the atomic and nanometer scale. The scope and limitations of the resolution of structural defects are discussed as a criterion for a true atomic resolution.

• Received 8 March 1993

DOI:https://doi.org/10.1103/PhysRevB.48.5675