Abstract

The measurand in dynamic force microscopy is the frequency shift, which is a direct function of the tip-sample interaction. In this work, this interaction is experimentally investigated in the parameter space of tip-sample distance and bias voltage. This three-dimensional database is theoretically described by a simple model of a Lennard-Jones potential superimposed with an electrostatic potential. The detailed study of the tip-sample interaction is essential for many scanning probe measurements and offers insight, e.g., into charge states of defects which are supposed to dominate the surface chemistry of many materials.