Morphological Characterization and Lumped Element Model of Graphene and Biochar Thick Films

Carbon based materials exhibit interesting mechanical, thermal and electrical properties which make them excellent contenders for use as fillers in composites as film. Graphene has been vastly used among the carbon-based materials. More recently eco-friendly carbon-based materials like biochar have emerged. The deployment of carbon-based materials in films needs to be studied since films are more versatile and permit the exploitation of electrical properties of such materials over circuits and systems. Typical circuits and systems exploiting electrical properties of novel materials perform a number of applications including sensing, detection, tunable devices and energy harvesting. In this paper, films composed of 9:1 graphene or biochar are deployed on a microstrip line. The morphological properties of graphene and biochar and their respective films are studied with Raman spectra and Field Emission Scanning Electron Microscope (FESEM). The electrical properties (four-point probe measurements and scattering parameter measurements) of the films. Low frequency measurements are used as starting point for circuit models estimating the lumped impedance of the films. From the morphological characterization it is shown that biochar films appear as granulates carbonaceous materials whereas graphene films contains several flakes forming a network. From the low frequency measurements and microwave characterization it is seen that graphene films are more conductive as compared to biochar films. In many applications, it is useful to know the surface impedance of the film since it varies on interaction with any external stimulus (variation of pressure, humidity, gas, etc.)

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Synthesis of Hydronium-Potassium Jarosites: The Effect of pH and Aging Time on Their Structural, Morphological, and Electrical Properties

Minerals ◽

10.3390/min11010080 ◽

2021 ◽

Vol 11 (1) ◽

pp. 80

Author(s):

Elías Hernández-Lazcano ◽

E. Cerecedo-Sáenz ◽

J. Hernández-Ávila ◽

Norman Toro ◽

T. V. K. Karthik ◽

...

Keyword(s):

Electrical Properties ◽

Aging Time ◽

Anode Materials ◽

Lithium Ion ◽

Rietveld Analysis ◽

Morphological Properties ◽

Particle Sizes ◽

Ph Values ◽

Hydronium Jarosite ◽

Cationic Site

Structural and morphological properties of hydronium-potassium jarosite microstructures were investigated in this work, and their electrical properties were evaluated. All the microstructures were synthesized at a very low temperature of 70 °C with a reduced reaction time of 3 h. An increase in the pH from 0.8 to 2.1 decreased the particle sizes from 3 µm to 200 nm and an increase in the aging time from zero, three, and seven days resulted in semispherical, spherical, and euhedral jarosite structures, respectively. The Rietveld analysis also confirmed that the amount of hydronium substitution by potassium in the cationic site increased with an increase in pH. The percentages of hydronium jarosite (JH)/potassium jarosite (JK) for pH values of 0.8, 1.1, and 2.1 were 77.72/22.29%, 82.44/17.56%, and 89.98/10.02%, respectively. Microstructures obtained in this work were tested as alternative anode materials and the voltage measured using these electrodes made with hydronium-potassium jarosite microstructures and graphite ranged from 0.89 to 1.36 V. The results obtained in this work show that with reduced particle size and euhedral morphology obtained, modified jarosite microstructures can be used as anode materials for improving the lifetime of lithium-ion batteries.

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Mechanical monolithic tiltmeter for low frequency measurements

10.1117/12.974587 ◽

2012 ◽

Author(s):

F. Acernese ◽

R. Canonico ◽

R. De Rosa ◽

G. Giordano ◽

R. Romano ◽

...

Keyword(s):

Low Frequency ◽

Frequency Measurements

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Graphene Oxide Layer-by-Layer Films for Sensors and Devices

Nanomaterials ◽

10.3390/nano11061556 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1556

Author(s):

Ivan C. C. Assunção ◽

Susana Sério ◽

Quirina Ferreira ◽

Nykola C. Jones ◽

Søren V. Hoffmann ◽

...

Keyword(s):

Graphene Oxide ◽

Electrical Properties ◽

Vacuum Ultraviolet ◽

Morphological Characterization ◽

Linear Increase ◽

Layer By Layer ◽

Absorption Bands ◽

Semiconductor Behavior ◽

Vacuum Ultraviolet Spectroscopy

Layer-by-layer films of poly (allylamine hydrochloride) (PAH) and graphene oxide (GO) were characterized, looking at growth with the number of bilayers, morphology, and electrical properties. The PAH/GO films revealed a linear increase in absorbance with the increase in the number of deposited bilayers, allowing the determination that 10.7 ± 0.1 mg m−2 of GO is adsorbed per unit of area of each bilayer. GO absorption bands at 146, 210, 247 and 299 nm, assigned to π-π* and n-π* transitions in the aromatic ring (phenol) and of the carboxylic group, respectively, were characterized by vacuum ultraviolet spectroscopy. The morphological characterization of these films demonstrated that they are not completely uniform, with a bilayer thickness of 10.5 ± 0.7 nm. This study also revealed that the films are composed of GO and/or PAH/GO fibers and that GO is completely adsorbed on top of PAH. The electrical properties of the films reveal that PAH/GO films present a semiconductor behavior. In addition, a slight decrease in conduction was observed when films were prepared in the presence of visible light, likely due to the presence of oxygen and moisture that contributes to the damage of GO molecules.

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Comparative electrical impedance spectroscopy study of graphene and indium tin oxide electrodes during low frequency measurements

2021 IEEE 15th International Symposium on Applied Computational Intelligence and Informatics (SACI) ◽

10.1109/saci51354.2021.9465546 ◽

2021 ◽

Author(s):

Alexandra Julia Hencz ◽

Gabor Szilagyi ◽

Nina Gyorfi ◽

Kristof Tenzlinger ◽

Aleksandar Szechenyi ◽

...

Keyword(s):

Impedance Spectroscopy ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Electrical Impedance ◽

Low Frequency ◽

Electrical Impedance Spectroscopy ◽

Spectroscopy Study ◽

Frequency Measurements ◽

Oxide Electrodes ◽

Impedance Spectroscopy Study

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Preliminary Study of Low Frequency Measurements of Precision Resistance in NIM

2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) ◽

10.1109/cpem.2018.8501027 ◽

2018 ◽

Author(s):

Yunfeng Lu ◽

Jianting Zhao ◽

Qing He

Keyword(s):

Low Frequency ◽

Frequency Measurements ◽

Preliminary Study

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Determination of Electric and Magnetic Properties of Commercial LTCC Soft Ferrite Material

Journal of Microelectronics and Electronic Packaging ◽

10.4071/imaps.286 ◽

2011 ◽

Vol 8 (1) ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Nelu Blaž ◽

Andrea Marić ◽

Goran Radosavljević ◽

Nebojša Mitrović ◽

Ibrahim Atassi ◽

...

Keyword(s):

Electrical Properties ◽

Low Frequency ◽

Hysteresis Loops ◽

Frequency Range ◽

Dispersion Parameters ◽

Simple Method ◽

Component Design ◽

Microwave Engineering ◽

Characterization Procedure

This paper offers an effective, accurate, and simple method for permittivity and permeability determination of an LTCC (low temperature cofired ceramic) ferrite sample. The presented research can be of importance in the fields of ferrite component design and application, as well as for RF and microwave engineering. The characterization sample is a stack of LTCC tapes forming a toroid. Commercially available ferrite tape ESL 40012 was used and standard LTCC processing was applied for the sample fabrication. For the first time, the electrical properties of a ferrite toroid sample of ESL 40012 LTCC ferrite tape is presented at various frequencies. The electrical properties of LTCC ferrite materials, permittivity and specific resistivity, are shown in a frequency range from 10 kHz to 1 MHz using the capacitive method. The hysteresis properties of this material are also determined. B-H hysteresis loops were measured applying a maximum excitation of 2 kA/m and frequencies of 50 Hz, 500 Hz, and 1000 Hz. Permeability is determined in the frequency range from 10 kHz to 1 GHz and a characterization procedure is divided in two segments, for low and high frequencies. Low frequency measurements (from 10 kHz to 1 MHz) are performed using LCZ meter and discrete turns of wire, while a short coaxial sample holder and vector network analyzer were used for the higher frequency range (from 300 kHz to 1 GHz). In addition, another important factor required for the practical design of devices is presented, the temperature variation of the permeability dispersion parameters.

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Fabrication of (ZnO)x: (Cu)1-x/PSi Solar Cell Using Laser Induced Plasma Technique

Journal of Physics Conference Series ◽

10.1088/1742-6596/2114/1/012028 ◽

2021 ◽

Vol 2114 (1) ◽

pp. 012028

Author(s):

G. H. Jihad ◽

K.A. Aadim

Keyword(s):

Solar Cell ◽

Electrical Properties ◽

Current Density ◽

Electrochemical Etching ◽

Average Diameter ◽

Etching Process ◽

Morphological Properties ◽

Etching Time ◽

Solar Cell Performance ◽

Cell Efficiency

Abstract Fabrication of PSi is generated successfully depending upon photo-electrochemical etching process. The purpose is to differentiate the characterization of the PSi monolayer based on c-silicon solar cell compared to the bulk silicon alone. The surface of ordinary p-n solar cell has been reconstructed on the n-type region of (100) orientation with resistivity (3.2.cm) in hydrofluoric (HF) acid at a concentration of 2 ml was used to in order to enhance the conversion efficiency with 10-minute etching time and current density of 50 mA/cm2, The morphological properties (AFM) as well as the electrical properties have been investigated (J-V). The atomic force microscopy investigation reveals a rugged silicon surface with porous structure nucleating during the etching process (etching time), resulting in an expansion in depth and an average diameter of (40.1 nm). As a result, the surface roughness increases. The electrical properties of prepared PS, namely current density-voltage characteristics in the dark, reveal that porous silicon has a sponge-like structure and that the pore diameter increases with increasing etching current density and the number of shots increasing this led that the solar cell efficiency was in the range of (1-2%), resulting in improved solar cell performance.

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Morphological characterization of gram-positive and gram-negative bacteria from treated latex processing wastewater

Environmental and Toxicology Management ◽

10.33086/etm.v1i2.2263 ◽

2021 ◽

Vol 1 (2) ◽

pp. 32-36

Author(s):

Farrah Aini Dahalan ◽

Nor Azizah Parmin

Keyword(s):

Oxygen Demand ◽

Morphological Characterization ◽

The Other ◽

Morphological Properties ◽

Morphological Observation ◽

Gram Positive ◽

Bacterial Colony ◽

Gram Negative ◽

Gram Staining

A preliminary morphological screening and isolation of bacterial colony from latex industrial wastewater was carried out. Bacteria colonies from latex processing wastewater were isolated from a local latex processing industry. It was found that 17 bacterial isolates had been purified grown on nutrient agar under 35˚C. The colonies were then purified and morphologically indicated via Gram staining and motility test. After morphological observation, it was identified that out of 17 isolates, 9 isolates were Gram positive and 8 isolates were Gram negative. There are 11 out of 17 colonies were rod-shaped bacterial colonies, while the other 6 colonies were cocci-shaped bacteria. There were 11 colonies of gliding bacteria, three colonies were non-motile bacteria and the other three colonies were flagellated bacteria. This study is only limited to morphological observation as the main aim of this study was to investigate the potential occurrence of viable growth in treated latex processing wastewater. The bacterial colonies were classified base on their morphological properties shown. This study has classified several genera such as Staphylococcus, Escherichia, Thiobacillus, Arthrobacter and other Genus. The growth curve of 17 isolates studied and the chemical oxygen demand were determined.

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