Conservative and dissipative tip-sample interaction forces probed with dynamic AFM

The conservative and dissipative forces between tip and sample of a dynamic atomic force microscopy (AFM) were investigated using a combination of com puter simulations and experimental AFM data obtained by the frequency modul ation technique. In this way it became possible to reconstruct complete for ce versus distance curves and damping coefficient versus distance curves fr om experimental data without using fit parameters for the interaction force and without using analytical interaction models. A comparison with analyti cal approaches is given and a way to determine a damping coefficient curve from experimental data is proposed. The results include the determination o f the first point of repulsive contact of a vibrating tip when approaching a sample. The capability of quantifying the tip-sample interaction is demon strated using experimental data obtained with a silicon tip and a mica samp le in UHV. [S0163-1829(99)01839-1].