Dresden 2006 – scientific programme
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O: Oberflächenphysik
O 27: Scanning probe techniques II
O 27.7: Talk
Tuesday, March 28, 2006, 17:15–17:30, WIL B321
Theoretical Analysis of Q-controlled Dynamic Force Microscopy in Ambient Conditions — •Daniel Ebeling1,2, Hendrik Hölscher1,2, Harald Fuchs1,2, and Udo D. Schwarz3 — 1Center for Nanotechnology (CeNTech), Münster — 2Physics Institute, University of Münster — 3Department of Mechanical Engineering, Yale University, New Haven, USA
The so-called Q-control method allows the active modification of the effective cantilever damping in dynamic force microscopy (DFM) by increasing or decreasing the Q-value of the cantilever [1]. This feature can be used in different ways to improve the imaging capabilities of DFM in air. Even though the Q-control method has been frequently applied in numerous experimental studies in recent years [2, 3] and the necessary driving electronics is commercially available, it is striking that an in-depth analytic description that would allow a rigorous theoretical explanation of the various features of Q-controlled dynamic force microscopy (QC-DFM) is still missing. Here, we present an analysis of QC-DFM based on the analytical solution of the equation of motion and on numerical simulations considering a model tip-sample interaction force in both cases. Explicit formulas allowing for the calculation of all relevant parameters like gain, phase, and amplitude are given. The detailed analysis of these formulas explains the observed imaging characteristics of QC-DFM.
[1] B. Anczykowski et al., Appl. Phys. A 66, S885 (1998)
[2] J. Tamayo et al., APL. 77, 582 (2000)
[3] A. Grant et al., Ultramicroscopy 97, 2919 (2003)