Quantitative Charge Imaging of Silicon Nanocrystals by Atomic Force Microscopy

2002 ◽  
Vol 737 ◽  
Author(s):  
Tao Feng ◽  
Harry A. Atwater
Keyword(s):  
Atomic Force Microscopy ◽  
Nonvolatile Memory ◽  
Electrostatic Force ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Si Nanocrystals ◽  
Nonvolatile Memory Devices ◽  
Quantitative Understanding ◽  
Simulated Images

ABSTRACTQuantitative understanding of charging and discharging of Si nanocrystals in SiO2 films on Si substrate is essential to their application in floating gate nonvolatile memory devices. Charge imaging by atomic force microscopy (AFM) or electrostatic force microscopy (EFM) can provide qualitative information on such system, while a further step is needed. We have developed a generalized method of images, which can solve Poisson equation for multiple dielectric layers, to simulate the charge imaging of Si nanocrystals by non-contact mode AFM under different sample geometries. Simulated images can be compared with experimental images thoroughly to estimate the total amount and distributions of trapped charges, which is also useful in the study of time evolution of charges or dissipation problems.

Multifrequency Atomic Force Microscopy: Compositional Imaging with Electrostatic Force Measurements

2011 ◽  
Vol 17 (4) ◽  
pp. 587-597 ◽  
Author(s):  
Sergei Magonov ◽  
John Alexander
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Potential ◽  
Electrostatic Interactions ◽  
Electrostatic Force ◽  
Contact Mode ◽  
Organic Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Intermittent Contact ◽  
Multicomponent Polymer

AbstractWe demonstrate that single-pass Kelvin force microscopy (KFM) and dC/dz measurements in different environments expand the compositional imaging with atomic force microscopy. The KFM and dC/dz studies were performed in the intermittent contact mode with force gradient detection of tip-sample electrostatic interactions. Both factors contribute to sensitive measurements of the surface potential and capacitance gradient with nanometer-scale spatial resolution as it was verified on a broad range of materials: metal alloys, polymers, organic layers, and liquid-like objects. For many samples the surface potential and dC/dz variations complement each other in identification of individual components of heterogeneous materials. In situ imaging in different humidity or vapors of various organic solvents further facilitate recognition of the constituents of multicomponent polymer samples due to selective swelling of components.

scholarly journals Dynamic friction energy dissipation and enhanced contrast in high frequency bimodal atomic force microscopy

Friction ◽  
2021 ◽  
Author(s):  
Xinfeng Tan ◽  
Dan Guo ◽  
Jianbin Luo
Keyword(s):  
Atomic Force Microscopy ◽  
Energy Dissipation ◽  
Contact Friction ◽  
Measuring Instruments ◽  
Dynamic Friction ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Friction Energy ◽  
New Applications

AbstractDynamic friction occurs not only between two contact objects sliding against each other, but also between two relative sliding surfaces several nanometres apart. Many emerging micro- and nano-mechanical systems that promise new applications in sensors or information technology may suffer or benefit from noncontact friction. Herein we demonstrate the distance-dependent friction energy dissipation between the tip and the heterogeneous polymers by the bimodal atomic force microscopy (AFM) method driving the second order flexural and the first order torsional vibration simultaneously. The pull-in problem caused by the attractive force is avoided, and the friction dissipation can be imaged near the surface. The friction dissipation coefficient concept is proposed and three different contact states are determined from phase and energy dissipation curves. Image contrast is enhanced in the intermediate setpoint region. The work offers an effective method for directly detecting the friction dissipation and high resolution images, which overcomes the disadvantages of existing methods such as contact mode AFM or other contact friction and wear measuring instruments.

scholarly journals Atomic force microscopy comparative analysis of the surface roughness of two posterior chamber phakic intraocular lens models: ICL versus IPCL

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juan Gros-Otero ◽  
Samira Ketabi ◽  
Rafael Cañones-Zafra ◽  
Montserrat Garcia-Gonzalez ◽  
Cesar Villa-Collar ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Intraocular Lenses ◽  
Posterior Chamber ◽  
Anterior Surface ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Phakic Intraocular Lenses ◽  
Roughness Measurements

Abstract Background To compare the anterior surface roughness of two commercially available posterior chamber phakic intraocular lenses (IOLs) using atomic force microscopy (AFM). Methods Four phakic IOLs were used for this prospective, experimental study: two Visian ICL EVO+ V5 lenses and two iPCL 2.0 lenses. All of them were brand new, were not previously implanted in humans, were monofocal and had a dioptric power of − 12 diopters (D). The anterior surface roughness was assessed using a JPK NanoWizard II® atomic force microscope in contact mode immersed in liquid. Olympus OMCL-RC800PSA commercial silicon nitride cantilever tips were used. Anterior surface roughness measurements were made in 7 areas of 10 × 10 μm at 512 × 512 point resolution. The roughness was measured using the root-mean-square (RMS) value within the given regions. Results The mean of all anterior surface roughness measurements was 6.09 ± 1.33 nm (nm) in the Visian ICL EVO+ V5 and 3.49 ± 0.41 nm in the iPCL 2.0 (p = 0.001). Conclusion In the current study, we found a statistically significant smoother anterior surface in the iPCL 2.0 phakic intraocular lenses compared with the VISIAN ICL EVO+ V5 lenses when studied with atomic force microscopy.

scholarly journals Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

2019 ◽  
Vol 10 ◽  
pp. 617-633 ◽  
Author(s):  
Aaron Mascaro ◽  
Yoichi Miyahara ◽  
Tyler Enright ◽  
Omur E Dagdeviren ◽  
Peter Grütter
Keyword(s):  
Atomic Force Microscopy ◽  
Electrostatic Force ◽  
Oscillation Period ◽  
Electrostatic Force Microscopy ◽  
Time Varying ◽  
Time Resolved ◽  
Battery Materials ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Techniques

Recently, there have been a number of variations of electrostatic force microscopy (EFM) that allow for the measurement of time-varying forces arising from phenomena such as ion transport in battery materials or charge separation in photovoltaic systems. These forces reveal information about dynamic processes happening over nanometer length scales due to the nanometer-sized probe tips used in atomic force microscopy. Here, we review in detail several time-resolved EFM techniques based on non-contact atomic force microscopy, elaborating on their specific limitations and challenges. We also introduce a new experimental technique that can resolve time-varying signals well below the oscillation period of the cantilever and compare and contrast it with those previously established.

Contact and non-contact mode imaging by atomic force microscopy

1996 ◽  
Vol 273 (1-2) ◽  
pp. 138-142 ◽  
Author(s):  
Seizo Morita ◽  
Satoru Fujisawa ◽  
Eigo Kishi ◽  
Masahiro Ohta ◽  
Hitoshi Ueyama ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force

Conducting Polymer nanoComposites (CPC): Nanocharacterisation of layer by layer sprayed PMMA-CNT vapour sensors by Atomic force Microscopy in current Sensing Mode (CS-AFM)

2008 ◽  
Vol 1143 ◽  
Author(s):  
Bijandra Kumar ◽  
Mickaël Castro ◽  
Jianbo Lu ◽  
Jean-François Feller
Keyword(s):  
Atomic Force Microscopy ◽  
Spray Deposition ◽  
Dynamic Mode ◽  
Layer By Layer ◽  
Initial State ◽  
Contact Mode ◽  
Current Sensing ◽  
Multi Wall Carbon Nanotubes ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTOrganic vapour sensors based on poly (methylmethacrylate)-multi-wall carbon nanotubes (PMMA-CNT) conductive polymer nanocomposite (CPC) were developed via layer by layer technique by spray deposition. CPC Sensors were exposed to three different classes of solvents (chloroform, methanol and water) and their chemo-electrical properties were followed as a function of CNTcontent in dynamic mode. Detection time was found to be shorter than that necessary for full recovery of initial state. CNT real three dimensional network has been visualized by Atomic force microscopy in a field assisted intermittent contact mode. More interestingly real conductive network system and electrical ability of CPC have been explored by current-sensing atomic force microscopy (CS-AFM). Realistic effect of voltage on electrical conductivity has been found linear.

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