Force spectroscopy using bimodal frequency modulation atomic force microscopy
Author
Aksoy, M. D.
Atalar, Abdullah
Date
2011-02-15Source Title
Physical Review B
Print ISSN
1098-0121
Publisher
American Physical Society
Volume
83
Issue
7
Language
English
Type
ArticleItem Usage Stats
116
views
views
98
downloads
downloads
Abstract
We propose a force-spectroscopy technique where a higher order mode of a cantilever is excited simultaneously with the first. Resonance tracking of both vibration modes through a frequency modulation scheme provides a way to extract topographical information and the gradient of the tip-sample interaction within a single surface scan. We provide an analytic treatment of the scheme, derive expressions relating frequency shifts of the higher mode and the tip-sample forces, and offer two methods of improving the accuracy of reconstruction of the force gradient. Finally, we confirm our predictions by numerical simulations.