The resonance frequency and Q-factor of cantilevers typically used for non-contact atomic force microscopy (NC-AFM) are measured as a function of the ambient pressure varied from 10 −8 mbar to normal pressure. The Q-factor is found to be almost constant up to a pressure in the range of 10 −2-10 −1 mbar and then decreases by about three orders of magnitude when increasing the pressure further to normal pressure. The decrease in the resonance frequency measured over the same pressure range amounts to less than 1% where a significant change is observed in the range of 10-10 3 mbar. The pressure dependence of the effective Q-factor and resonance frequency is approximated by analytical models accounting for different processes in the molecular and viscous flow regimes. By introducing a heuristic approach for describing the pressure dependence in the transition regime, we are able to well approximate the cantilever properties over the entire pressure range.

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We implement a test bed allowing the characterisation of cantilevers used in non-contact atomic force microscopy under controlled atmospheric conditions prior to using the cantilevers in a force microscope. The effective Q-factor of two types of cantilevers is measured as a function of the ambient pressure varied from 10 −8 mbar to normal pressure. The Q-factor is found to be almost constant up to a pressure in the range of 10 −2 to 10 −1 mbar and then decreases by about three ordes of magnitude when increasing the pressure further to normal pressure. The pressure dependence of the effective Q-factor is approximated by analytical models based on the intrinsic damping of the cantilever, mounting losses and pressure dependent terms accounting for damping in the molecular flow and viscous regimes. The experimental data can be well described by the models in both regimes.