Multifrequency AFM integrating PeakForce tapping and higher eigenmodes for heterogeneous surface characterization

• Yanping Wei,
• Jiafeng Shen,
• Yirong Yao,
• Xuke Li,
• Ming Li and
• Peiling Ke

Beilstein J. Nanotechnol. 2025, 16, 2077–2085, doi:10.3762/bjnano.16.142

• kHz on our instrument) induces cantilever oscillations at the fundamental eigenmode frequency. These oscillations persist as decaying vibrations after tip–sample detachment (Figure 2D). To avoid interference from this parasitic vibration, we employed higher eigenmodes (i.e., second and third modes) to

Cantilever signature of tip detachment during contact resonance AFM

• Devin Kalafut,
• Ryan Wagner,
• Maria Jose Cadena,
• Anil Bajaj and
• Arvind Raman

Beilstein J. Nanotechnol. 2021, 12, 1286–1296, doi:10.3762/bjnano.12.96

• on how the cantilever motion evolves when this essential condition is violated. This is not an uncommon occurrence since higher operating amplitudes tend to yield better signal-to-noise ratio, so users may inadvertently reduce their experimental accuracy by inducing tip–sample detachment in an effort

• to improve their measurements. We shed light on this issue by deliberately pushing both our experimental equipment and numerical simulations to the point of tip–sample detachment to explore cantilever dynamics during a useful and observable threshold feature in the measured response. Numerical

• connect the qualitative and quantitative behavior to experimental features. Keywords: atomic force microscopy (AFM); contact resonance; nonlinear normal mode (NNM); tip–sample detachment; photothermal excitation; Introduction Contact resonance atomic force microscopy (CR-AFM) [1][2], piezoresponse force