Distance dependence of force and dissipation in non-contact atomic force microscopy on Cu(100) and Al(111)

Oliver Pfeiffer (1) , Laurent Nony (2) , Roland Bennewitz (3) , Alexis Baratoff (1) , Ernst Meyer (1)

1 NCCR - Institute of Physics
2 L2MP - Laboratoire matériaux et microélectronique de Provence
3 Institute of Physics [Basel]

The dynamic characteristics of a tip oscillating in the nc-AFM mode in close vicinity to a Cu(100)-surface are investigated by means of phase variation experiments in the constant amplitude mode. The change of the quality factor upon approaching the surface deduced from both frequency shift and excitation versus phase curves yield to consistent values. The optimum phase is found to be independent of distance. The dependence of the quality factor on distance is related to 'true' damping, because artefacts related to phase misadjustment can be excluded. The experimental results, as well as on-resonance measurements at different bias voltages on an Al(111) surface, are compared to Joule dissipation and to a model of dissipation in which long-range forces lead to viscoelastic deformations.

Mots clés: Non-contact AFM; dissipation; Visco elastic deformations; analytical models; metals

Domaines: Agrégats Moléculaires et Atomiques [physics.atm-clus]

Oliver Pfeiffer, Laurent Nony, Roland Bennewitz, Alexis Baratoff, Ernst Meyer. Distance dependence of force and dissipation in non-contact atomic force microscopy on Cu(100) and Al(111). Nanotechnology, 2004, 15, pp.S101-S107. ⟨10.1088/0957-4484/15/2/021⟩. ⟨hal-00014042⟩