scholarly journals Insights into dynamic sliding contacts from conductive atomic force microscopy

2020 ◽  
Vol 2 (9) ◽  
pp. 4117-4124
Author(s):  
Nicholas Chan ◽  
Mohammad R. Vazirisereshk ◽  
Ashlie Martini ◽  
Philip Egberts
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Sliding Contact ◽  
Current Transport ◽  
Conductive Atomic Force Microscopy ◽  
Sliding Contacts ◽  
Force Microscopy ◽  
Single Asperity ◽  
Atomic Force ◽  
Sliding Dynamics

Measuring the electrical conductivity serves as a proxy for characterizing the nanoscale contact. In this work, the correlation between sliding dynamics and current transport at single asperity sliding contact is investigated.

Lateral uniformity of the transport properties of graphene/4H-SiC (0001) interface by nanoscale current measurements

2009 ◽  
Vol 1205 ◽  
Author(s):  
Filippo Giannazzo ◽  
Sushant Sonde ◽  
Jean-Roch Huntzinger ◽  
Antoine Tiberj ◽  
Rositza Yakimova ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Buffer Layer ◽  
Dirac Point ◽  
Current Transport ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Fermi Level Pinning ◽  
Barrier Heights ◽  
Atomic Force ◽  
Positively Charged

AbstractConductive Atomic Force Microscopy was applied to study the lateral uniformity of current transport at the interface between graphene and 4H-SiC, both in the case of epitaxial graphene (EG) grown on the Si face of 4H-SiC and in the case of graphene exfoliated from HOPG and deposited (DG) on the same substrate. This comparison is aimed to investigate the role played by the C-rich buffer layer present at EG/4H-SiC interface and absent in the case of DG/4H-SiC. The distribution of the local Schottky barrier heights at EG/4H-SiC interface (ΦEG) was compared with the distribution measured at DG/4H-SiC interface (ΦDG), showing that ΦEG (0.36±0.1eV ) is ˜0.49eV lower than ΦDG (0.85 ± 0.06eV). This difference is explained in terms of the Fermi level pinning ˜0.49eV above the Dirac point in EG, due to the presence of positively charged states at the interface between the Si face of 4H-SiC and the buffer layer.

scholarly journals Measurements of the Electrical Conductivity of Monolayer Graphene Flakes Using Conductive Atomic Force Microscopy

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2575
Author(s):  
Soomook Lim ◽  
Hyunsoo Park ◽  
Go Yamamoto ◽  
Changgu Lee ◽  
Ji Won Suk
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Monolayer Graphene ◽  
Synthesis Methods ◽  
Clear Understanding ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Flakes

The intrinsic electrical conductivity of graphene is one of the key factors affecting the electrical conductance of its assemblies, such as papers, films, powders, and composites. Here, the local electrical conductivity of the individual graphene flakes was investigated using conductive atomic force microscopy (C-AFM). An isolated graphene flake connected to a pre-fabricated electrode was scanned using an electrically biased tip, which generated a current map over the flake area. The current change as a function of the distance between the tip and the electrode was analyzed analytically to estimate the contact resistance as well as the local conductivity of the flake. This method was applied to characterize graphene materials obtained using two representative large-scale synthesis methods. Monolayer graphene flakes synthesized by chemical vapor deposition on copper exhibited an electrical conductivity of 1.46 ± 0.82 × 106 S/m. Reduced graphene oxide (rGO) flakes obtained by thermal annealing of graphene oxide at 300 and 600 °C exhibited electrical conductivities of 2.3 ± 1.0 and 14.6 ± 5.5 S/m, respectively, showing the effect of thermal reduction on the electrical conductivity of rGO flakes. This study demonstrates an alternative method to characterizing the intrinsic electrical conductivity of graphene-based materials, which affords a clear understanding of the local properties of individual graphene flakes.

scholarly journals Metal-Conductive Polymer Core-Shell Nanowires: Electroless Reduction of Pd and Cu On Polypyrrole/DNA Templates Bearing 2-2'-Bipyridyl Groups

2020 ◽  
pp. 406-423
Author(s):  
Mahdi Almaky ◽  
Reda Hassanien ◽  
William Clegg ◽  
Ross Harrington ◽  
Andrew Houlton ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Metal Ion ◽  
Conductive Polymer ◽  
Hybrid Nanostructures ◽  
Conductive Atomic Force Microscopy ◽  
Cu Nanowires ◽  
Force Microscopy ◽  
Atomic Force ◽  
Uniform Manner

A method for the preparation of conductive polymer nanowires bearing metal ion chelating 2,2’-bipyridyl groups is described. N-(3-pyrrol-1-yl-propyl)-2,2'-bipyridinium hexafluorophosphate (NP2PBH) was templated on λ-DNA in aqueous solution using FeCl3 as oxidant to initiate polymerization. The polyNP2PBH/DNA nanowires were then decorated with metals (Cu or Pd) by electroless deposition [Cu(NO3)2/ascorbate or PdCl42-/NaBH4]. UV-vis absorption spectra of the hybrid materials show the absorption peak due to the plasmon resonance of Cu at about 550 nm and a broad continuous band consistent with metallic Pd in the range 300−700 nm. The morphology, size and electrical properties of the hybrid nanostructures have been characterized using scanning probe techniques (atomic force microscopy (AFM), scanning conductance microscopy (SCM) and conductive atomic force microscopy (cAFM)). The polyNP2PBH/DNA nanowires show a continuous, smooth and uniform appearance (mean diameter 5.0 nm). Cu deposits on polyNP2PBH/DNA nanowires by a nucleation and growth process that leads eventually to smooth, conductive Cu nanowires. In contrast, Pd deposits in a non-uniform manner on polyNP2PBH/DNA and has inconsistent electrical conductivity. The electrical conductivity of single Cu/polyNP2PBH/DNA nanowires was estimated to be 1.6 ± 0.27 S cm-1 which we suggest is limited by electron transfer between Cu grains.

Direct investigation of current transport in cells by conductive atomic force microscopy

2019 ◽  
Vol 277 (1) ◽  
pp. 49-57
Author(s):  
W. ZHAO ◽  
L.‐Z. CHEONG ◽  
S. XU ◽  
W. CUI ◽  
S. SONG ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Current Transport ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Direct Investigation ◽  
In Cells

Investigation of TiO2 Ceramic Surface Conductivity Using Conductive Atomic Force Microscopy

2012 ◽  
Vol 527 ◽  
pp. 154-158 ◽  
Author(s):  
Kristaps Rubenis ◽  
Karlis Kundzins ◽  
Janis Locs ◽  
Jurijs Ozolins
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Polarized Light ◽  
Ceramic Surface ◽  
Atmospheric Conditions ◽  
X Ray Diffraction ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Microscopy Technique ◽  
Atomic Force

Dense TiO2 (rutile) ceramic samples were prepared by sintering compacts of titanium dioxide anatase powder at 1500 °C for 5h. Sintered samples were polished and annealed in vacuum at 1000 °C for 1h. Structural properties of the samples were studied by X-ray diffraction, polarized light and scanning electron microscopy. The surface topography and local electrical conductivity of the samples were investigated by atomic force microscopy technique under atmospheric conditions. Enhanced electrical conductivity was observed at grain boundaries while the polished, vacuum annealed grains surface showed non-homogeneous conductivity.

Fault Isolation of MOL and FEOL Buried Defects Using Conductive Atomic Force Microscopy as a Complement to Passive Voltage Contrast Imaging

2017 ◽  
Author(s):  
Lucile C. Teague Sheridan ◽  
Linda Conohan ◽  
Chong Khiam Oh
Keyword(s):  
Atomic Force Microscopy ◽  
Cmos Technology ◽  
Fault Isolation ◽  
Contrast Imaging ◽  
Conductive Atomic Force Microscopy ◽  
Isolation Technique ◽  
Conductive Afm ◽  
Force Microscopy ◽  
Atomic Force ◽  
Voltage Contrast

Abstract Atomic force microscopy (AFM) methods have provided a wealth of knowledge into the topographic, electrical, mechanical, magnetic, and electrochemical properties of surfaces and materials at the micro- and nanoscale over the last several decades. More specifically, the application of conductive AFM (CAFM) techniques for failure analysis can provide a simultaneous view of the conductivity and topographic properties of the patterned features. As CMOS technology progresses to smaller and smaller devices, the benefits of CAFM techniques have become apparent [1-3]. Herein, we review several cases in which CAFM has been utilized as a fault-isolation technique to detect middle of line (MOL) and front end of line (FEOL) buried defects in 20nm technologies and beyond.

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