Characterization Of Electrical Properties Research Articles

Synthesis and characterization of structure, emission and electrical properties of MgxZn1−xO films obtained by spray pyrolysis with different Mg precursors

Synthesis and characterization of structure, emission and electrical properties of MgxZn1−xO films obtained by spray pyrolysis with different Mg precursors

In-situ rapid nondestructive characterization of multiple irregular three-dimensional grain boundary structures and electrical properties by nanorobot with SEM in ZnO

To address the problem of spatial quantification of irregular grain boundaries, a unique approach for the nondestructive characterization of multiple irregular three-dimensional grain boundaries is proposed using nanorobots with scanning electron microscopy (SEM) to accomplish in-situ rapid synchronized quantification of structures and electrical properties. By constructing a three-dimensional trigonometric geometric mapping relationship, multiple irregular three-dimensional grain boundary structures and electrical properties can be rapidly quantified. Experimental results demonstrate that it is feasible to accomplish in-situ rapid nondestructive characterizations. The two-dimensional profile shapes of the targeted grain boundaries at each layer exhibit irregular and non-uniform features in the Y-Z plane. The hypotenuse length between the virtual space tilting lines presents a three-dimensional characteristic in the X-Z plane. The spatial tilt angle of the virtual space tilting line can be calculated using the right-triangle relation. The unequal numbers of grains along the same tilted hypotenuse direction with equal lengths directly illustrate the existence of irregular and nonlinear grain boundaries in bulk ZnO ceramics. The relatively uniform spatial sizes of the grain boundary illustrate the coupled spatial characteristics existing in the irregular micro-structures. The relatively uniform equivalent circuit fitting parameters confirm the existence of relatively uniform doping components in bulk ZnO ceramics. Furthermore, this method provides a unique approach for the rapid nondestructive quantitative analysis of multiple three-dimensional irregular grain boundaries in bulk polycrystalline materials.

Experimental and DFT investigations of Al-doped ZnO nanostructured thin films

Al doped ZnO thin films at different concentrations have been successfully synthesized, characterized experimentally, and investigated theoretically by density functional theory (DFT). The crystal structure analysis was carried out using X-ray diffraction (XRD) data. Wurtzite structures of a single phase with a preferred orientation along the (002) plane are obtained. The surface morphology has been investigated by atomic force microscopy (AFM) which showed homogeneous and compact surfaces with spherical shape grains that change to a wave like nematic structure with increasing Al doping rate. For a complete characterization, experimental and theoretical analysis of optical and electrical properties have been done using UV–Vis spectrophotometry, the four-probe method, electronic band structure and density of states calculations, and the Boltz-Trap code based on the semi classical theory of Boltzmann. Both, experimental and theoretical, studies indicate an increase in gap energy with high transparency in the visible region and electrical conductivity improvement due to a non-localized state around the Fermi level. The experimental and theoretical studies agree well and show a similar tendency of the results. Therefore, these properties of Al-doped ZnO open a new avenue for optoelectronic and photonic device applications.

Characterization of electrical conductivity and dielectric properties of electroless NiP/rGO composite coated hemp fiber with various weight% of rGO and coating duration

The present study made an attempt to develop a conductive hemp fiber (HF) through an electroless Ni-P composite coating with reduced graphene oxide (rGO) as reinforcement. Four different Ni-P/rGO coated fibers were prepared with the variations in the coating time (20/40 min) and weight percentages of rGO (5/10 %). The coated fibers were characterized using various tools like: Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM), to identify the functional groups, phase structure, and morphological changes, induced by the rGO reinforcement. The coating duration and weight percentage of rGO had influenced the dielectric properties and electrical conductivity. In comparison, the coating duration of 40 min with 10 % addition of rGO has enhanced the electrical conductivity to 13.75 % and 37.5 % respectively. Furthermore, the mechanism behind the improvement in the conductivity is detailed in this study.

Enhanced electrical, optical and magnetic properties of BiFeO3 perovskite nanoparticles co-doped with Y and Cu

The present work includes the fabrication of pure BiFeO3 and Bi0.9Y0.1Fe1−xCuxO3 (x = 0.05, 0.10, 0.15) nanoparticles by the usual sol-gel route. The characterization of structural, morphological, optical, electrical, and magnetic properties of the synthesized samples was achieved through x-ray diffraction spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, an impedance analyzer, and a vibrating sample magnetometer. The Fourier transform infrared study confirmed the presence of Bi–O and Fe–O bonds. The x-ray diffraction patterns confirmed the rhombohedral (R3c) structure as a major phase with the orthorhombic (Pnma) structure as a secondary phase in all samples, and few amount of impurity phase of Bi25FeO40 was also determined. The surface morphology analysis showed the variation of particle size from 63 to 174 nm. The Raman spectra of 13 optical phonon modes, including 4A1 and 9E symmetric phonons, are observed for all samples, and the positions of these modes are almost similar, except the intensities of A1 modes. The optical measurements show a reduction in bandgap from 2.17 to 2.03 eV with co-doping, revealing itself as a more promising applicant in photovoltaics. An enhanced value of the dielectric constant is observed for different doped samples at different frequency regions from 100 Hz to 10 MHz. Magnetic investigation demonstrates the improved ferromagnetism with co-doping of Y and Cu due to distortion in the FeO6 octahedron. A maximum saturation magnetization of 0.26 emu/gm and a coercivity of 2915 Oe were found for Y concentration of 10% and Cu concentration of 15%.

Pulsed ultrasound assisted extraction of alternative plant protein from sugar maple leaves: Characterization of physical, structural, thermal, electrical, and techno-functional properties

Plant proteins are gaining in popularity and are increasingly being considered as an alternative to animal protein, thus a sustainable, yet comparable source of plant protein is highly recommended. To this end, the current study was conducted to investigate the structural, thermal, physical, and functional attributes, as well as the volatile profile of sugar maple leaves (SML) protein. To this end, SML protein was extracted by homogenization (10000 rpm, 5 min) pretreated ultrasound-assisted extraction (120000 J, 60% amplitude, 5:5 pulse, 25 °C, and 15 min) at varying pH (8−10) and compared with conventionally extracted SML protein. Among the different protein extracts, sonicated extract (pH9) provided a good protein yield (up to 7%) having higher protein content (210 mg Bovine serum albumin/g dry matter), thermal stability (onset of denaturation temperature:114 °C), and functional properties (solubility, emulsion capacity, water holding capacity, and antioxidant activity). On contrary, the characteristic green aroma, caused by 3-hexen-1-ol and nonanal, was found higher in sonicated protein extracts than that of macerated extracts. Having said that, this study showed the versatile properties of SML protein fractions that can be used as plant-based food ingredients.

Synthesis, morphology and electrical property characteristics of MXene based titanium carbide (Ti3C2Tx) coating on non-woven cotton paper

In the present study, Ti3C2Tx type MXene was prepared by selective etching of Al from Ti3AlC2 with mesh size of 200. The powder form of raw material was used to fabricate Ti3C2Tx by in-situ HF etching method. The MXene is further coated on non-woven paper by simply dip coating method. The detailed structural, morphology and elemental content study of as prepared Ti3C2Tx MXene have demonstrated. The MXene (Ti3AlC2) powders show compact, layered morphology as expected for bulk layered ternary carbide. The detailed elemental analysis has carried out for Titanium carbide based MXene coated and uncoated woven paper. The lower conducting property obtained for paper coating due less amount of coating in the surface of paper instead of coating on glass substrate. The electrical property characterization of MXene coated non-woven paper and glass substrate have also been studied. Hence, the conductive coating of MXene-in water formulation achieved through simple dip coating methods is promising for low cost sensor, wearable shielding device fabrication towards renewable energy and healthcare applications.

Using multilayer structures to enhance the electrical properties of porous silicon for thermal sensing

Porous silicon holds great promise as an optically and electrically tuneable material platform for high performance thermo-resistive sensing. Fulfilling this promise requires the ability to independently control the two critical parameters which determine the sensitivity (specifically the minimum temperature difference resolution) of thermal detectors: the temperature coefficient of resistance (TCR) and 1/f noise of the sensing material. In single porosity films these two properties are monolithically dependent, with both TCR and 1/f noise constant increasing with porosity. Here we show that use of multilayer films allows manipulation of properties of the overall structure to simultaneously achieve high TCR and low 1/f noise. Characterization of electrical properties of various porosity combinations revealed that using a two-layer heterostructure on Si substrate with low porosity (48 %) as the top layer and a high porosity (80 %) as the lower layer, both high TCR (∼ 4.4 %/K) and low 1/f noise constant (4 × 10−13) could be simultaneously achieved. This transforms the ability to exploit porous silicon for future high sensitivity based thermal detectors.

Correction to: Structural and electrical property characterization of thermoelectric (Ca3Co4O9+δ) ceramic oxide fabrication by various reducing agent method

Correction to: Structural and electrical property characterization of thermoelectric (Ca3Co4O9+δ) ceramic oxide fabrication by various reducing agent method

Synthesis and characterization of structural, magnetic and electrical properties of Mn substituted Co-Zn ferrite

Spinel – type Zn0.5Co0.5 - xMnxFe2O3 ferrites were synthesized via solid-state reaction method with x values of 0.0, 0.1, 0.2, 0.3, and 0.4. X-ray diffraction was used to identify the crystallographic structure, which revealed the formation of a single-phase cubic spinel structure. The lattice parameter of Co-Zn ferrite samples was measured with a maximum value of 8.76 Å, and the density decreased with increasing concentration. The average grain size decreased with increasing Mn concentration. The Vibrating sample magnetometry (VSM) technique confirmed the soft ferromagnetic character of the entire sample, with a maximum magnetic saturation value of 73.67 emu/g, which was decreased with increasing Mn concentration. The magnetic coercivity (Oe) value led to a slightly hard magnetic phase with increasing Mn concentration, with a maximum value of 6.22. AC resistivity and permeability decreased with increasing frequency but were more activated at lower frequency, which is typical for ferrite behavior. The resistivity and dielectric constant correlated with the value of porosity and bulk density with increasing Mn percentage.

Cellular excitability and ns-pulsed electric fields: Potential involvement of lipid oxidation in the action potential activation

Recent studies showed that nanosecond pulsed electric fields (nsPEFs) can activate voltage-gated ion channels (VGICs) and trigger action potentials (APs) in excitable cells. Under physiological conditions, VGICs’ activation takes place on time scales of the order 10–100 µs. These time scales are considerably longer than the applied pulse duration, thus activation of VGICs by nsPEFs remains puzzling and there is no clear consensus on the mechanisms involved. Here we propose that changes in local electrical properties of the cell membrane due to lipid oxidation might be implicated in AP activation. We first use MD simulations of model lipid bilayers with increasing concentration of primary and secondary lipid oxidation products and demonstrate that oxidation not only increases the bilayer conductance, but also the bilayer capacitance. Equipped with MD-based characterization of electrical properties of oxidized bilayers, we then resort to AP modelling at the cell level with Hodgkin-Huxley-type models. We confirm that a local change in membrane properties, particularly the increase in membrane conductance, due to formation of oxidized membrane lesions can be high enough to trigger an AP, even when no external stimulus is applied. However, excessive accumulation of oxidized lesions (or other conductive defects) can lead to altered cell excitability.

Advance of microfluidic flow cytometry enabling high-throughput characterization of single-cell electrical and structural properties.

This paper reported a micro flow cytometer capable of high-throughput characterization of single-cell electrical and structural features based on constrictional microchannels and deep neural networks. When single cells traveled through microchannels with constricted cross-sectional areas, they effectively blocked concentrated electric field lines, producing large impedance variations. Meanwhile, the traveling cells were confined within the cross-sectional areas of the constrictional microchannels, enabling the capture of high-quality images without losing focuses. Then single-cell features from impedance profiles and optical images were extracted from customized recurrent and convolution networks (RNN and CNN), which were further fused for cell-type classification based on support vector machines (SVM). As a demonstration, two leukemia cell lines (e.g., HL60 vs. Jurkat) were analyzed, producing high-classification accuracies of 99.3% based on electrical features extracted from Long Short-Term Memory (LSTM) of RNN, 96.7% based on structural features extracted from Resnet18 of CNN and 100.0% based on combined features enabled by SVM. The microfluidic flow cytometry developed in this study may provide a new perspective for the field of single-cell analysis.

The Effect of Heat Treatment on Crystalline, Electrical and Optical Properties of ZnO/PVA Nanocomposites

ZnO/PVA nanocomposites have been successfully synthesized using the spin coating method by using synthesized ZnO, ZnO nanoparticles as filler, and PVA as a matrix. The synthesized films were treated at temperatures of 70, 90, and 120 °C. Some characterizations, such as I-V, UV-Vis, XRD, and SEM, have been carried out to study the electrical, crystalline, and optical properties of ZnO/PVA nanocomposites. The characterization of electrical properties using I-V measurements showed that ZnOsynthesized/PVA had a high current value of 1.55 nA, while ZnOnano/PVA had a smaller current value of 1.49 nA when treated at 120 °C. In addition, the higher the treatment temperature, the greater the resistance of ZnOsynthesized/PVA and ZnOnano/PVA. UV-Vis characterization showed that ZnOnano/PVA experienced a red shift when the temperature increased, while ZnOsynthesized/PVA and ZnOnano/PVA when treated at 120 °C experienced a blue shift. XRD characterization of ZnOnano/PVA showed that the higher the given temperature, the lower the crystallinity, from 45.77 to 34.81%. SEM characterization showed that ZnOnano/PVA at room temperature agglomerated and formed larger particles.

에폭시화된 대두유와 Trisalicyl Borate 고분자의 전기적 특성 분석 및 연구

에폭시화된 대두유와 Trisalicyl Borate 고분자의 전기적 특성 분석 및 연구

An impedance flow cytometry with integrated dual microneedle for electrical properties characterization of single cell

Electrical characteristics of living cells have been proven to reveal important details about their internal structure, charge distribution and composition changes in the cell membrane, as well as the extracellular context. An impedance flow cytometry is a common approach to determine the electrical properties of a cell, having the advantage of label-free and high throughput. However, the current techniques are complex and costly for the fabrication process. For that reason, we introduce an integrated dual microneedle-microchannel for single-cell detection and electrical properties extraction. The dual microneedles utilized a commercially available tungsten needle coated with parylene. When a single cell flows through the parallel-facing electrode configuration of the dual microneedle, the electrical impedance at multiple frequencies is measured. The impedance measurement demonstrated the differential of normal red blood cells (RBCs) with three different sizes of microbeads at low and high frequencies, 100 kHz and 2 MHz, respectively. An electrical equivalent circuit model (ECM) was used to determine the unique membrane capacitance of individual cells. The proposed technique demonstrated that the specific membrane capacitance of an RBC is 9.42 mF/m−2, with the regression coefficients, at 0.9895. As a result, this device may potentially be used in developing countries for low-cost single-cell screening and detection.

Synthesis, Characterization and Investigation of Optical and Electrical Properties of Polyaniline/Nickel Ferrite Composites.

Nickel ferrite nanoparticles are prepared by using a low-temperature self-propagating solution combustion method using urea as fuel. The prepared nickel ferrite nanoparticles were doped with polyaniline in the three different weight ratios of 10%, 30% and 50% by using an in situ polymerization method and by adding ammonium persulfate as an oxidizing agent. The obtained samples were characterized by using XRD, FTIR, SEM and a UV-visible spectrophotometer. XRD examined crystalline peaks of ferrites and amorphous peak of polyaniline and confirmed the formation of the composites. FTIR examined the chemical nature of samples and showed peaks due to polyaniline and the characteristic peaks that were less than 1000 cm-1 wavenumber were due to metal-oxygen bond vibrations of ferrites. AC conductivity increased with frequency in all samples and the highest AC conductivity was seen in polyaniline/nickel ferrite 50%. DC conductivity increased in all samples with the temperature showing the semiconducting nature of the samples. Activation energy was evaluated by using Arrhenius plots and there was a decrease in activation energy with the addition of ferrite content. The UV-visible absorption peaks of polyaniline showed shifting in the composites. The optical direct and indirect band gaps were evaluated by plotting Tauc plots and the values of the optical band gap decreased with addition of ferrite in polyaniline and the Urbach energy increased in the samples with 10%, 30% and 50% polyaniline/nickel ferrite composites. The optical properties of these composites with a low band gap can find applications in devices such as solar cells.

Evaluating the Accuracy of Impedance Flow Cytometry with Cell-Sized Liposomes.

Electrical properties of single cells are important label-free biomarkers of disease and immunity. At present, impedance flow cytometry (IFC) provides important means for high throughput characterization of single-cell electrical properties. However, the accuracy of the spherical single-shell electrical model widely used in IFC has not been well evaluated due to the lack of reliable and reproducible single-shell model particles with true-value electrical parameters as benchmarks. Herein, a method is proposed to evaluate the accuracy of the single-cell electrical model with cell-sized unilamellar liposomes synthesized through double emulsion droplet microfluidics. The influence of three key dimension parameters (i.e., the measurement channel width w, height h, and electrode gap g) in the single-cell electrical model were evaluated through experiment. It was found that the relative error of the electrical intrinsic parameters measured by IFC is less than 10% when the size of the sensing zone is close to the measured particles. It further reveals that h has the greatest influence on the measurement accuracy, and the maximum relative error can reach ∼30%. Error caused by g is slightly larger than w. This provides a solid guideline for the design of IFC measurement system. It is envisioned that this method can advance further improvement of IFC and accurate electrical characterization of single cells.

A green synthetic approach for C/Ag@ urchin-like TiO2 nanocomposites showing a highly molar ratio CH4/CO for CO2 photoreduction

In the paper, the urchin-like TiO2 with rutile crystal structure was prepared under acidic conditions. When C powder was added in the reaction process, rutile TiO2 became rutile and anatase diphase structure. The yields of CH4 and CO of C/Ag@TiO2 were 5.46 μmol·g−1·h−1 and 1.51 μmol·g−1·h−1, respectively, and the molar ratio of CH4 was the highest for 78.3%. Through characterization of optical and electrical properties, the addition of C and Ag improved the optical performance, carrier concentration, and electron mobility. Finally, the photocatalytic reaction mechanism was proposed.

PiRT-IFC: Physics-informed real-time impedance flow cytometry for the characterization of cellular intrinsic electrical properties

Real-time transformation was important for the practical implementation of impedance flow cytometry. The major obstacle was the time-consuming step of translating raw data to cellular intrinsic electrical properties (e.g., specific membrane capacitance Csm and cytoplasm conductivity σcyto). Although optimization strategies such as neural network-aided strategies were recently reported to provide an impressive boost to the translation process, simultaneously achieving high speed, accuracy, and generalization capability is still challenging. To this end, we proposed a fast parallel physical fitting solver that could characterize single cells’ Csm and σcyto within 0.62 ms/cell without any data preacquisition or pretraining requirements. We achieved the 27000-fold acceleration without loss of accuracy compared with the traditional solver. Based on the solver, we implemented physics-informed real-time impedance flow cytometry (piRT-IFC), which was able to characterize up to 100,902 cells’ Csm and σcyto within 50 min in a real-time manner. Compared to the fully connected neural network (FCNN) predictor, the proposed real-time solver showed comparable processing speed but higher accuracy. Furthermore, we used a neutrophil degranulation cell model to represent tasks to test unfamiliar samples without data for pretraining. After being treated with cytochalasin B and N-Formyl-Met-Leu-Phe, HL-60 cells underwent dynamic degranulation processes, and we characterized cell’s Csm and σcyto using piRT-IFC. Compared to the results from our solver, accuracy loss was observed in the results predicted by the FCNN, revealing the advantages of high speed, accuracy, and generalizability of the proposed piRT-IFC.

Synthesis and characterization of dielectric, electric, and magnetic properties of vanadium doped-bismuth europium ferrites for multiferroic applications

Polycrystalline Bi0.90Eu0.10Fe1-xVxO3 (BEFVO) (where x = 0.00 to 0.10) ceramics were synthesized by the solid-state reaction method. The X-ray diffraction (XRD) pattern revealed that all the samples possess hexagonal crystal structures with some impurity peaks. Gold Schmidt’s tolerance factor of the samples was found 0.8436 to 0.8478 which represents more stability of the doped BiFeO3 (BFO) than parent BFO. The crystallite size was found in the range of 65–33 nm. The density gradually increases with increasing the V concentration and the maximum bulk density (ρB = 6.981 g/cm3) is obtained for the x = 0.10 sample. The obtained average grain size is found in the micrometer range and the values are in the range of 1.31–0.74 µm. The maximum dielectric constant of 2577 at 102 Hz is found for the x = 0.07 sample. The resistivity decreases with doping concentration as a result of ac conductivity increases. The highest transition frequency of long-range to short-range mobility of charge carriers is obtained for the x = 0.07 sample. The highest real part of the initial permeability of 25.24 is found for x = 0.07 multiferroic ceramics. For the x = 0.07 sample, the maximal saturation magnetization is found to be 1.91 emu/g. The studied samples comprise large electric polarization and the optimum polarization of 7.5 μc/cm2 is observed for the x = 0.07 composition.