The application of single-pass multifrequency Kelvin probe force microscopy (KPFM) for topography and contact potential difference (CPD) measurements of organic self-assembled monolayers (SAM) is demonstrated. Four modes of mechanical and electrical cantilever excitation were tested in order to obtain the best possible resolution in the CPD measurements. The algorithm using maximum capacity of information channel for quantitative image quality assessment was proposed to compare and assess the quality of the recorded images and imaging modes. The improvement of the quality of CPD imaging in multiresonance operation was confirmed.
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http://dx.doi.org/10.1016/j.ultramic.2018.08.002 | DOI Listing |
Light Sci Appl
November 2023
Hyperspectral Nano-imaging Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea.
We, for the first time, report the nanoscopic imaging study of anomalous infrared (IR) phonon enhancement of bilayer graphene, originated from the charge imbalance between the top and bottom layers, resulting in the enhancement of E mode of bilayer graphene near 0.2 eV. We modified the multifrequency atomic force microscope platform to combine photo-induced force microscope with electrostatic/Kelvin probe force microscope constituting a novel hybrid nanoscale optical-electrical force imaging system.
View Article and Find Full Text PDFBeilstein J Nanotechnol
September 2022
School of Physics and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin, D04 V1W8, Ireland.
In this paper, we derive and present quantitative expressions governing the performance of single and multifrequency Kelvin probe force microscopy (KPFM) techniques in both air and water. Metrics such as minimum detectable contact potential difference, minimum required AC bias, and signal-to-noise ratio are compared and contrasted both off resonance and utilizing the first two eigenmodes of the cantilever. These comparisons allow the reader to quickly and quantitatively identify the parameters for the best performance for a given KPFM-based experiment in a given environment.
View Article and Find Full Text PDFScience
April 2021
Physikalisches Institut, Universität Stuttgart, 70569 Stuttgart, Germany.
Geometrical frustration, quantum entanglement, and disorder may prevent long-range ordering of localized spins with strong exchange interactions, resulting in an exotic state of matter. κ-(BEDT-TTF)Cu(CN) is considered the prime candidate for this elusive quantum spin liquid state, but its ground-state properties remain puzzling. We present a multifrequency electron spin resonance (ESR) study down to millikelvin temperatures, revealing a rapid drop of the spin susceptibility at 6 kelvin.
View Article and Find Full Text PDFActa Biomater
February 2021
Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK. Electronic address:
The shapes of living organisms are formed and maintained by precise control in time and space of growth, which is achieved by dynamically fine-tuning the mechanical (viscous and elastic) properties of their hierarchically built structures from the nanometer up. Most organisms on Earth including plants grow by yield (under pressure) of cell walls (bio-polymeric matrices equivalent to extracellular matrix in animal tissues) whose underlying nanoscale viscoelastic properties remain unknown. Multifrequency atomic force microscopy (AFM) techniques exist that are able to map properties to a small subgroup of linear viscoelastic materials (those obeying the Kelvin-Voigt model), but are not applicable to growing materials, and hence are of limited interest to most biological situations.
View Article and Find Full Text PDFJ Neuroimaging
July 2019
Department of Radiology, Stanford University, Stanford, CA.
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