Local Structure and Dynamics Studied by Force Modulation Spectroscopy and Imaging
William J. Price, P K. Kuo, T R. Lee, Z C. Ying, Gang-Yu Liu
Using nanoengineered structures of self-assembled monolayers on gold, asystematic investigation was conducted to study the sensitivity of force modulation AFM to molecular level packing, domain boundaries, and chemical functionality. Tip-surface contact was found to exhibit resonances that were highly sensitive to local structure and environment. In addition, the amplitude and phase images are less susceptible to the tip convolution allowing better resolution of domain boundaries, edges of nanostructures, step edges and other surface defects. Most importantly, force modulation probes the contact dynamics, which makes AFM an active technique in addition to probing static features such as local topography and frictional variations. By tuning the driving frequencies to a local tip-surface resonance frequency, specific surface features such as edges of domains and nanostructures, specific components, or desired chemicalfunctionalities, could be selectively enhanced. This active probing technique provides a new paradigm in materials characterization and the study of nanotribology by AFM.
atomic force microscopy, force modulation, nanocharacterization, nanostructure, self-assembled monolayer
, Kuo, P.
, Lee, T.
, Ying, Z.
and Liu, G.
Local Structure and Dynamics Studied by Force Modulation Spectroscopy and Imaging, Langmuir
(Accessed December 2, 2023)