2 research outputs found
Phase contrast in tapping-mode scanning force microscopy
The tapping-mode operation of a scanning force
microscope represents an intermediate situation between contact and noncontact regimes. Its rapid development and expansion are due to lateral force minimization and its ability to
give phase-contrast images of heterogeneous surfaces. Here,
we calculate the phase shift between the cantilever excitation
and its response as a function of the sample mechanical properties, tipâsample separation, and adhesion forces. We show
that the phase shift that gives rise to phase-contrast images
is associated with tipâsample interactions that involve energy
dissipation such as adhesion energy hysteresis and viscoelasticity. Experimental phase-shift measurements performed on
mica surfaces support the conclusions of the model.This work has been supported by DirecciĂłn General de
InvestigaciĂłn CientĂïŹca y TĂ©cnica of Spain (DGICYT) (PB94-0016).Peer reviewe