Blog Posts
DFRT Revisited - From Feedback Optimization to Full Data Acquisition
on 18.02.2020 by Romain Stomp
How to Achieve More Stable Z-feedback in FM-AFM Mode
on 15.05.2014 by Romain Stomp
Related products: MFLI, HF2LI, UHFLI, MF-MD, HF2LI-MF, UHF-MF
Multi-frequency techniques in atomic force microscopy (MF-AFM) can discriminate many different contributions from the tip-sample interaction in the form of mechanical, electric, magnetic, or optical responses. MF-AFM is also sensitive to non-linear effects causing a harmonic distortion from the steady-state motion of the oscillating cantilever. As most AFM sensors exhibit different eigenmodes up to a few MHz, the ability to actuate and detect such modes separately can be exploited and adapted to measure various physical phenomena. For example, bimodal excitation, dual-harmonic Kelvin probe, multi-harmonic mode, and many SNOM or tip-enhanced techniques often make use of higher harmonic generation.
Demodulating many frequency components simultaneously from one or multiple inputs is a key requirement for multi-frequency techniques. The choice of a measurement setup depends on whether information is mostly contained in the eigenmodes (that is, the natural modes of vibration of the resonator), in the harmonics (i.e., integer multiples of the fundamental tone), or in both. We can nonetheless distinguish three different measurement strategies for MF-AFM:
Broad measurement capabilities and tunable modulation parameters are therefore crucial for the design and optimization of the experimental setup.
on 18.02.2020 by Romain Stomp
on 15.05.2014 by Romain Stomp