Dissipation processes of an oscillating microlever in non-contact resonantmode: a mechanical approach

The abrupt increase of the damping coefficient of an oscillating microlever in the proximity of a surface is discussed as a direct consequence of a lo cal relaxation. The power law found and the dependence of the damping coeff icient on the oscillation amplitude are in good agreement with the experime ntal data recorded on a graphite surface. We show that a combined study of the resonance frequency shift and of the dissipation should bring new infor mation on the intrinsic mechanical properties of a surface at a local scale .