Article
Engineering, Electrical & Electronic
Ryota Fukuzawa, Daichi Kobayashi, Takuji Takahashi
Summary: Electrostatic force microscopy (EFM) is used to examine the electrostatic force between an AFM tip and sample surface, allowing evaluation of their capacitance and surface potential. The dependences of the electrostatic force on dc voltage and ac voltage frequency can be used to investigate carrier density, carrier type, and deep-level states in a semiconductor. Proper distance control is necessary in EFM to ensure accurate measurements, and the oscillation amplitude of a cantilever can be effectively used for feedback control. The 1 A-mode operation in EFM shows good robustness against the strong electrostatic force and allows proper measurements of tip-sample capacitance.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Chemistry, Physical
Robert D. E. Henderson, Carina T. Filice, Shawn Wettig, Zoya Leonenko
Summary: This study provides direct evidence of electrostatic interactions between gemini surfactant molecules and DNA strands on a cellular level, visualized using KPFM and correlated with their topography from AFM. The difference in topography and electrical surface potential between monolayers with and without DNA is significant, with strongly positive relative electrical surface potential observed in between lipid domains and DNA strands. These results suggest that cationic surfactant molecules likely surround DNA strands within a sea of background lipids.
Article
Chemistry, Multidisciplinary
Sayanti Samaddar, Jeff Strasdas, Kevin Janssen, Sven Just, Tjorven Johnsen, Zhenxing Wang, Burkay Uzlu, Sha Li, Daniel Neumaier, Marcus Liebmann, Markus Morgenstern
Summary: By studying the current-induced surface potential maps of graphene field-effect transistors, it was discovered that electron-electron scattering dominates in certain areas, exhibiting viscous flow phenomena, even at moderate mobility.
Article
Chemistry, Physical
Myung Gi Ji, Qiang Li, Rana Biswas, Jaeyoun Kim
Summary: Experimental study of nanopatterned tribocharges on elastomer surfaces revealed distinct fast and slow decay components attributed to different tribocharging mechanisms, providing insights into the temporal behavior and stability of tribocharges at the nanoscale level.
Article
Physics, Applied
Xu Liang, Yiwen Yu, Ruijia Liu, Wenyuan Liu, Shengping Shen
Summary: By using PFM and Kelvin probe force microscopy, the electromechanical coupling properties of periodically poled lithium niobite were qualitatively and quantitatively determined, with the indication that the flexoelectric effect may play a crucial role in electromechanical coupling in PPLN thin films.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Multidisciplinary
Hubert Grzywacz, Michal Milczarek, Piotr Jenczyk, Wojciech Dera, Marcin Michalowski, Dariusz M. Jarzabek
Summary: This study presents the results of nanoscale friction measurements using an Atomic Force Microscope calibrated with a precise nanoforce sensor. The coefficient of friction was found to strongly depend on the applied load, probe type, scanning velocity, and film thickness.
Article
Chemistry, Physical
Woosuk Choi, Raj Kumar Bera, Seung Won Han, Hongjun Park, Tae Won Go, Minkee Choi, Ryong Ryoo, Jeong Young Park
Summary: The effect of nitrogen and sulfur doping on zeolite-templated carbon was investigated. It was found that nitrogen-doped zeolite-templated carbon had different composition ratios and electrical conductances depending on the synthesis temperature. The doped materials showed low ohmic drop and high capacitance when used as supercapacitor electrode materials. The doping effect was explained by measuring the work function.
Article
Chemistry, Multidisciplinary
Emilie Gachon, Patrick Mesquida
Summary: Collagen fibrils exhibit a surface charge dependency on longitudinal strain, becoming more positive within 10% strain and more negative between 10% to 17% strain. This change is correlated with fibril stiffness and may be influenced by structural rearrangements. Kelvin-probe force microscopy testing on fibrils attached to an extensible, thin polymer film allows for the determination of electrical surface potential.
Article
Chemistry, Multidisciplinary
Marti Checa, Ruben Millan-Solsona, Adrianna Glinkowska Mares, Silvia Pujals, Gabriel Gomila
Summary: Mapping the dielectric properties of cells with nanoscale spatial resolution is crucial for nanomedicine and nanotoxicity analysis, complementing structural and mechanical measurements. This study demonstrates the feasibility of obtaining dielectric constant maps of fixed cells in liquid environments, which helps preserve cell structure while accessing local dielectric properties under fully hydrated conditions. Further developments are needed to address the nanoscale dielectric imaging of living cells.
Article
Chemistry, Physical
Maki Hiraoka, Nobuyuki Ishida, Akio Matsushita, Ryusuke Uchida, Takeyuki Sekimoto, Teruaki Yamamoto, Taisuke Matsui, Yukihiro Kaneko, Kenjiro Miyano, Masatoshi Yanagida, Yasuhiro Shirai
Summary: Kelvin probe force microscopy was used to monitor the potential profile in lead-halide perovskite photovoltaic cells. By studying various devices under different conditions, quantitative profile features were deduced and used to compare against numerical calculations. The technique was applied to devices before and after degradation, allowing the identification of degraded components and inference of performance loss sources.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Chin Chyi Loo, Sha Shiong Ng, Wei Sea Chang
Summary: The increasing interest in manipulating the polarization of piezo/ferroelectric materials using light has led to more studies on their light-polarization interaction. This paper demonstrates the caution needed when analyzing and interpreting data from piezoresponse force microscopy (PFM) experiments, as the photo-induced surface charge interacts electrostatically with the tip, causing significant photo-response in the PFM amplitude image. Through photo-assisted Kelvin probe force microscopy (KPFM), it is found that positive surface potential is developed near the sample's surface under 405 nm light illumination, and its effects on the measured PFM signal are revealed through comparative studies. This work highlights the importance of complementary use of KPFM, PFM imaging mode, and PFM spectroscopy mode to distinguish genuine behavior from artifacts.
MICROSCOPY AND MICROANALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Devon S. Jakob, Nengxu Li, Huanping Zhou, Xiaoji G. Xu
Summary: This article introduces a novel method to generate Coulombic force in KPFM, increasing the spatial resolution to approximately 25 nm. By integrating PiFM, high spatial resolution chemical distributions and surface potential maps can be obtained concurrently. This is expected to facilitate characterizations of nanoscale electrical properties of photoactive materials, semiconductors, and ferroelectric materials.
Article
Chemistry, Physical
Owoong Kwon, Seunghun Kang, Sanghyun Jo, Yun Do Kim, Hee Han, Yeehyun Park, Xiaoli Lu, Woo Lee, Jinseong Heo, Marin Alexe, Yunseok Kim
Summary: Ferroelectric materials have been widely used in various fields due to their switchable spontaneous polarization. With the decrease in characteristic sizes of devices and materials below the nanoscale, appropriate characterization tools have become essential. A novel method based on high-frequency AFM-PUND has been proposed for measuring polarization-voltage hysteresis loops, showing promising results in evaluating nanoscale polarization values of ferroelectrics.
Article
Chemistry, Multidisciplinary
Victor G. Gisbert, Carlos A. Amo, Miriam Jaafar, Agustina Asenjo, Ricardo Garcia
Summary: Bimodal AFM operated in a bimodal configuration enables high quantitative accuracy and high-spatial resolution mapping of magnetic interactions, providing a self-evaluation protocol to test the accuracy of measurements and supporting the application of mapping long-range magnetic interactions quantitatively.
Article
Chemistry, Multidisciplinary
Mengkang Xu, Xinpeng Tian, Qian Deng, Qun Li, Shengping Shen
Summary: By introducing nanocracks and applying continuously varying mechanical loading, the evolution of flexoelectricity around the crack tips in SrTiO3, Ba0.67Sr0.33TiO3, and TiO2 samples has been successfully measured. This method provides a reliable way to identify the significance of the flexoelectric effect and may open a new avenue for the study of flexoelectricity involving multiple physics phenomena such as flexoelectronics and the flexo-photovoltaic effect.
