Regensburg 2016 – wissenschaftliches Programm

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MI: Fachverband Mikrosonden

MI 5: Scanning Probe Microscopy

MI 5.1: Vortrag

Mittwoch, 9. März 2016, 16:00–16:15, H5

Contrast of nonlinear response in atomic force microscopy — •Daniel Forchheimer^1,2, Robert Forchheimer³, and David Haviland¹ — ¹Royal Institute of Technology (KTH), Stockholm, Sweden — ²Intermodulation Products AB, Segersta, Sweden — ³Linköping University, Linköping, Sweden

A trend in Atomic Force Microscopy (AFM) is towards obtaining more information without increasing the measurement time. This can be achieved by driving the AFM cantilever at multiple frequencies simultaneously, so-called multifrequency AFM. Such drive schemes creates motion not only at the driven frequencies but also at harmonics and mixing frequencies, due to the nonlinear behavior of the force between the tip and the surface with respect to their separation. Although these nonlinear frequency components are weaker by at least an order of magnitude compared to the amplitude at the drive frequencies, we show that they provide excellent contrast when imaging heterogenous materials such as a polymer blend. Multifrequency AFM data also warrants new methods of analysis. We demonstrate how algorithms from the field of machine learning can be used to improve the contrast of images or blindly cluster data of different regions into specific groups.

Reference: D. Forchheimer, R. Forchheimer, D. B. Haviland, Nature Communications, 6, 6270 (2015).