Influence of noncontact dissipation in the tapping mode: Attempt to extract quantitative information on the surface properties with the local force probe method

摘要

In the Tapping mode, a variation of the oscillation amplitude and phase as afunction of the tip sample distance is the necessary measurement to accessquantitatively to the properties of the surface. In the present work, we give asystematic comparison between experimental data recorded on two surfaces, phaseand amplitude, and theoretical curves. With an interaction between the tip andthe surface taking into account an attractive and a repulsive term, theanalytical approach is unable to properly describe the relationship between thephase variation and the oscillation amplitude variation. When an additionaldissipation term is involved, due to the attractive interaction between the tipand the surface, the model gives a good agreement with the recorded data.Particularly, the trends in the phase variations related to the noncontactsituations have been found to be amenable to an analysis based upon a simpleviscoelastic behavior of the surface.