Tip-surface interactions in dynamic atomic forcemicroscopy
(English)Manuscript (preprint) (Other academic)
In atomic force microscopy (AFM) tip-surface interactions are usuallyconsidered as functions of the tip position only, so-called force curves. However,tip-surface interactions often depend on the tip velocity and the past tip trajectory.Here, we introduce a compact and general description of these interactionsappropriate to dynamic AFM where the measurement of force is restricted toa narrow frequency band. We represent the tip-surface interaction in termsof a force disk in the phase space of position and velocity. Determination ofthe amplitude dependence of tip-surface forces at a fixed static probe heightallows for a comprehensive treatment of conservative and dissipative interactions.We illuminate the fundamental limitations of force reconstruction with narrowband dynamic AFM and we show how the amplitude dependence of the F ouriercomponent of the force at the tip oscillation frequency, gives qualitative insight intothe detailed nature of the tip-surface interaction. With minimal assumptions thisamplitude dependence force spectroscopy allows for a quantitative reconstruction ofthe effective conservative tip-surface force as well as a position-dependent dampingfactor. We demonstrate this reconstruction on simulated intermodulation AFMdata.
atomic force microscopy, measurement of force, mechanical resonators, MEMS/NEMS, dissipation, intermodulation
IdentifiersURN: urn:nbn:se:kth:diva-122581OAI: oai:DiVA.org:kth-122581DiVA: diva2:622854
FunderSwedish Research CouncilVinnova
QS 20132013-05-232013-05-232013-05-27Bibliographically approved