Abstract

In attempting to perform frequency modulation atomic force microscopy (FM-AFM) in liquids, a non-flat phase transfer function in the self-excitation system prevents proper tracking of the cantilever natural frequency. This results in frequency-and-phase modulation atomic force microscopy (FPM-AFM) which lies in between phase modulation atomic force microscopy (PM-AFM) and FM-AFM. We derive the theory necessary to recover the conservative force and damping in such a situation, where standard FM-AFM theory no longer applies. Although our recovery procedure applies to all cantilever excitation methods in principle, its practical implementation may be difficult, or even impossible, if the cantilever is driven piezoacoustically. Specifically, we contrast the piezoacoustic excitation method to the photothermal method in the context of force spectroscopy of hydration structures at the mica-water interface. The results clearly demonstrate that photothermal excitation is superior to piezoacoustic excitation, as it allows for accurate quantitative interpretation of the acquired data. Copyright 2011 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [doi:10.1063/1.3601872]

Comments

Copyright (2011) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in AIP Advances 1, 022136 (2011) and may be found at http://dx.doi.org/10.1063/1.3601872. The following article has been submitted to/accepted by AIP Advances. Copyright (2011) A. Labuda, K. Kobayashi, D. Kiracofe, K. Suzuki, P. H. Grütter and H. Yamada. This article is distributed under a Creative Commons Attribution 3.0 Unported License.

Keywords

CANTILEVERS; ENERGY

DOI

10.1063/1.3601872

Citation

AIP Advances 1, 022136 (2011)

Date of this Version

6-2011

Download

Share

COinS