Berlin 2015 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 101: Scanning Probe Techniques: AFM
O 101.2: Talk
Friday, March 20, 2015, 10:45–11:00, MA 144
Information in multifrequency AFM data — •Daniel Platz1,2, Daniel Forchheimer2, Erik A. Tholén3, John E. Sader4, and David B. Haviland2 — 1Max-Planck-Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, D-01187 Dresden, Germany — 2KTH Royal Institute of Technology, Albanova University Center, SE-114 19 Stockholm, Sweden — 3Intermodulation Products AB, Vasavägen 29, SE - 169 58 Solna, Sweden — 4The University of Melbourne, Victoria 3010, Australia
In contrast to conventional amplitude or frequency-modulated AFM, multifrequency AFM is characterized by tip motion that contains more than one single oscillation frequency. The additional frequency components might be generated by a nonlinear tip-surface force, a multifrequency drive scheme, or both. Each frequency component is usually considered as an individual channel carrying information about the tip-surface interaction. However, it is generally not understood exactly which information about the tip-surface force is encoded in each of the individual frequency components. We present a clear definition of "information" in the context of multifrequency AFM, and we introduce a general method, called numerical kernel estimate (NKE), for the analysis of multifrequency AFM spectra. We demonstrate the capabilities of NKE by applying it to the analysis of Intermodulation AFM. This analysis reveals the fundamental limitations of force measurement from spectral data. Moreover, we use NKE also for the design of new multifrequency drive schemes that are optimal for the extraction of a maximum amount of information about the tip-surface force.