scholarly journals Ultimate High Conductivity of Multilayer Graphene Examined by Multiprobe Scanning Tunneling Potentiometry on Artificially Grown High-Quality Graphite Thin Film

2019 ◽  
Vol 1 (9) ◽  
pp. 1762-1771
Author(s):  
Hiroyuki Mogi ◽  
Takafumi Bamba ◽  
Mutsuaki Murakami ◽  
Yuki Kawashima ◽  
Masamichi Yoshimura ◽  
...  
Keyword(s):  
Thin Film ◽  
High Conductivity ◽  
Scanning Tunneling ◽  
Multilayer Graphene ◽  
High Quality

Scanning Tunneling Microscopy Study of Single Domain β-SiC(100) Surfaces: Growth and Morphology

1998 ◽  
Vol 05 (01) ◽  
pp. 207-211 ◽  
Author(s):  
F. Semond ◽  
L. Douillard ◽  
P. Soukiassian ◽  
A. Mayne ◽  
G. Dujardin ◽  
...  
Keyword(s):  
Thin Film ◽  
Scanning Tunneling Microscopy ◽  
Microscopy Study ◽  
Single Domain ◽  
Scanning Tunneling ◽  
Low Density ◽  
Tunneling Microscopy ◽  
High Quality ◽  
Scanning Tunneling Microscopy Study

We investigate single domain β-SiC(100) thin film surfaces epitaxially grown on a vicinal (4°) Si(100) surface by atom-resolved (filled and empty states) scanning tunneling microscopy (STM). Contrary to previous beliefs, we observe high quality surfaces having a low density of defects. The β-SiC(100)-(3×2) surface, which is a Si-rich surface, is achieved by sequences of Si deposition and surface annealings. This results in the growth and coalescence of large Si islands and/or vacancies islands having the 3×2 array. Our results indicate the formation of asymmetric Si-Si dimers all tilted in the same direction and forming rows in a 3×2 arrangement at a 1/3 Si mon/layer coverage.

scholarly journals Current Noise in Thick and Thin Film Resistors

1983 ◽  
Vol 10 (2-3) ◽  
pp. 81-85 ◽  
Author(s):  
S. Demolder ◽  
A. Van Calster ◽  
M. Vandendriessche
Keyword(s):  
Thin Film ◽  
Thick Film ◽  
Measured Data ◽  
Measuring Circuit ◽  
Current Noise ◽  
High Quality ◽  
Thin Film Resistors

In this paper a sensitive measuring circuit is described for the measurement of current noise on high quality thin and thick film resistors. Measured data on resistors are presented and analysed.

scholarly journals Development and Comparative Analysis of Electrochemically Etched Tungsten Tips for Quartz Tuning Fork Sensor

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 286
Author(s):  
Ashfaq Ali ◽  
Naveed Ullah ◽  
Asim Ahmad Riaz ◽  
Muhammad Zeeshan Zahir ◽  
Zuhaib Ali Khan ◽  
...  
Keyword(s):  
Tuning Fork ◽  
Mechanical Stability ◽  
Electrochemical Etching ◽  
Research Work ◽  
Cone Angle ◽  
Quartz Tuning Fork ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
High Quality ◽  
Scanning Electron

Quartz Tuning Fork (QTF) based sensors are used for Scanning Probe Microscopes (SPM), in particular for near-field scanning optical microscopy. Highly sharp Tungsten (W) tips with larger cone angles and less tip diameter are critical for SPM instead of platinum and iridium (Pt/Ir) tips due to their high-quality factor, conductivity, mechanical stability, durability and production at low cost. Tungsten is chosen for its ease of electrochemical etching, yielding high-aspect ratio, sharp tips with tens of nanometer end diameters, while using simple etching circuits and basic electrolyte chemistry. Moreover, the resolution of the SPM images is observed to be associated with the cone angle of the SPM tip, therefore Atomic-Resolution Imaging is obtained with greater cone angles. Here, the goal is to chemically etch W to the smallest possible tip apex diameters. Tips with greater cone angles are produced by the custom etching procedures, which have proved superior in producing high quality tips. Though various methods are developed for the electrochemical etching of W wire, with a range of applications from scanning tunneling microscopy (SPM) to electron sources of scanning electron microscopes, but the basic chemical etching methods need to be optimized for reproducibility, controlling cone angle and tip sharpness that causes problems for the end users. In this research work, comprehensive experiments are carried out for the production of tips from 0.4 mm tungsten wire by three different electrochemical etching techniques, that is, Alternating Current (AC) etching, Meniscus etching and Direct Current (DC) etching. Consequently, sharp and high cone angle tips are obtained with required properties where the results of the W etching are analyzed, with optical microscope, and then with field emission scanning electron microscopy (FE-SEM). Similarly, effects of varying applied voltages and concentration of NaOH solution with comparison among the produced tips are investigated by measuring their cone angle and tip diameter. Moreover, oxidation and impurities, that is, removal of contamination and etching parameters are also studied in this research work. A method has been tested to minimize the oxidation on the surface and the tips were characterized with scanning electron microscope (SEM).

Solid-state reaction process for high-quality organometallic halide perovskite thin film

2021 ◽  
Vol 227 ◽  
pp. 111014
Author(s):  
Chien-Chung Hsu ◽  
Sheng-Min Yu ◽  
Kun-Mu Lee ◽  
Chuan-Jung Lin ◽  
Hao-Chien Cheng ◽  
...  
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Solid State Reaction ◽  
Reaction Process ◽  
High Quality ◽  
Halide Perovskite

High conductivity and transparent aluminum-based multi-layer source/drain electrodes for thin film transistors

2018 ◽  
Vol 51 (6) ◽  
pp. 065103 ◽  
Author(s):  
Rihui Yao ◽  
Hongke Zhang ◽  
Zhiqiang Fang ◽  
Honglong Ning ◽  
Zeke Zheng ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
High Conductivity

scholarly journals A High Rigidity and Precision Scanning Tunneling Microscope with Decoupled XY and Z Scans

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Xu Chen ◽  
Tengfei Guo ◽  
Yubin Hou ◽  
Jing Zhang ◽  
Wenjie Meng ◽  
...  
Keyword(s):  
Scanning Tunneling Microscope ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Electronic Noise ◽  
High Quality ◽  
Tunneling Microscope ◽  
The Core ◽  
High Rigidity ◽  
The Common ◽  
The Impact

A new scan-head structure for the scanning tunneling microscope (STM) is proposed, featuring high scan precision and rigidity. The core structure consists of a piezoelectric tube scanner of quadrant type (for XY scans) coaxially housed in a piezoelectric tube with single inner and outer electrodes (for Z scan). They are fixed at one end (called common end). A hollow tantalum shaft is coaxially housed in the XY-scan tube and they are mutually fixed at both ends. When the XY scanner scans, its free end will bring the shaft to scan and the tip which is coaxially inserted in the shaft at the common end will scan a smaller area if the tip protrudes short enough from the common end. The decoupled XY and Z scans are desired for less image distortion and the mechanically reduced scan range has the superiority of reducing the impact of the background electronic noise on the scanner and enhancing the tip positioning precision. High quality atomic resolution images are also shown.

Thermal Performance of Different Carbonaceous Nanoparticles as Additives to Thermal Paste as an Interface Material

2021 ◽  
Author(s):  
Bharath Bharadwaj ◽  
Prashant Singh ◽  
Roop L. Mahajan
Keyword(s):  
Thermal Performance ◽  
Heat Dissipation ◽  
High Conductivity ◽  
The Other ◽  
Multilayer Graphene ◽  
Optimum Level ◽  
Thermal Paste ◽  
Nano Additives ◽  
Thermal Pastes ◽  
Interface Materials

Abstract With increased focus on miniature high power density electronic packages, there is a need for the development of new interface materials with lower thermal resistance. To this end, high conductivity thermal paste or similar thermal interface materials (TIMs), reinforced with superior thermal conductivity materials such as multi-walled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs), graphite-derived multilayer graphene (g-MLG) offer an effective strategy to provide efficient paths for heat dissipation from heat source to heat sink. In an earlier paper, we had demonstrated that multilayer graphene derived from coal (coal-MLG) synthesized using our in-house developed one-pot process, has increased presence of phenolic groups on its surfaces, which translates into better dispersion of coal-MLG in silicone thermal paste. In this paper, we first compare the thermal conductance of a high conductivity thermal paste (k = 8.9 W/mK) using coal-MLG as an additive with that realized with other nano additives — MWCNTs, GNPs, and g-MLG. The data shows that coal-MLG as an additive outperforms all the other investigated nano additives in enhancing the thermal performance of the paste. With the coal-MLG as an additive, ∼70% increase in thermal performance was observed as compared to the base thermal paste used. This increase is about 2.5 times higher than that obtained using g-MLG as an additive. We also measured the thermal performance of coal-MLG-based TIM with its different wt.% fractions. The data confirmed our hypothesis that the optimum level of the loading fraction of the additive that can be dispersed in the matrix (paste in this case) before the onset of agglomeration is higher for the coal-MLG (3%) than for the other additives (2%). The implication is further improvement thermal performance with coal-MLG. The data shows the additional thermal enhancement to ∼2X. Finally, since coal-MLG produced by our in-house process is relatively cheaper and more environmentally friendly, we believe that these results would pave the path for enhanced thermal performance with non-silicone thermal pastes at a significantly lower cost. We also expect similar benefits for the silicone-based thermal pastes.

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