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Non-contact atomic force microscopy (nc-AFM), also known as dynamic force microscopy (DFM), is a mode of atomic force microscopy, which itself is a type of scanning probe microscopy. In nc-AFM a sharp probe is moved close (order of Angstroms ) to the surface under study, the probe is then raster scanned across the surface, the image is then ...
Non-contact mode AFM does not suffer from tip or sample degradation effects that are sometimes observed after taking numerous scans with contact AFM. This makes non-contact AFM preferable to contact AFM for measuring soft samples, e.g. biological samples and organic thin film. In the case of rigid samples, contact and non-contact images may ...
The feedback loop is particularly important in non-contact AFM techniques, particularly in pc-AFM. As previously mentioned, in non-contact mode the cantilever is stationary and the tip does not come into physical contact with the sample surface. [36] The cantilever behaves as a spring and oscillates at its resonance frequency.
Traditional contact resonance AFM requires an external actuator to excite the cantilever contact resonances. In AFM-IR these contact resonances are automatically excited every time an infrared pulse is absorbed by the sample. So the AFM-IR technique can measure the infrared absorption by the amplitude of the cantilever oscillation response and ...
The first mode relies on the AFM contact mode, and the second mode of operation employs a scanning thermal microscopy probe (invented in 1986 [20]) to measure the polymer's temperature increase. In 2007, AFM was combined with infrared attenuated total reflection (IR-ATR) spectroscopy to study the dissolution process of urea in a cyclohexane ...
In this mode the cantilever is oscillated at a resonant frequency of the cantilever and the AFM tip is held such that it only senses with long range electrostatic forces without entering the repulsive contact regime. In this non-contact regime, the electric force gradient causes a shift in the resonance frequency of the cantilever.
SKP has been used to investigate the surface potential of materials used in solar cells, with the advantage that it is a non-contact, and therefore a non-destructive technique. [28] It can be used to determine the electron affinity of different materials in turn allowing the energy level overlap of conduction bands of differing materials to be ...
This type of AFM operation is referred to as the force mode. With this probe, one can study interactions between various surfaces and probe particles in the sphere-plane geometry . It is also possible to study forces between colloidal particles by attaching another particle to the substrate and perform the measurement in the sphere-sphere ...