scholarly journals Capacitive-Coupling Impedance Spectroscopy Using a Non-Sinusoidal Oscillator and Discrete-Time Fourier Transform: An Introductory Study

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6392
Author(s):  
Tomiharu Yamaguchi ◽  
Akinori Ueno
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Capacitive Coupling ◽  
Capacitively Coupled ◽  
Coupling Capacitance ◽  
Sinusoidal Oscillator ◽  
In Series ◽  
Multiple Frequencies ◽  
Short Time ◽  
Complex Impedance Spectra

In this study, we propose a new short-time impedance spectroscopy method with the following three features: (1) A frequency spectrum of complex impedance for the measured object can be obtained even when the measuring electrodes are capacitively coupled with the object and the precise capacitance of the coupling is unknown; (2) the spectrum can be obtained from only one cycle of the non-sinusoidal oscillation waveform without sweeping the oscillation frequency; and (3) a front-end measuring circuit can be built, simply and cheaply, without the need for a digital-to-analog (D-A) converter to synthesize elaborate waveforms comprising multiple frequencies. We built the measurement circuit using the proposed method and then measured the complex impedance spectra of 18 resistive elements connected in series with one of three respective capacitive couplings. With this method, each element’s resistance and each coupling’s capacitance were estimated independently and compared with their nominal values. When the coupling capacitance was set to 10 nF or 1.0 nF, estimated errors for the resistive elements in the range of 2.0–10.0 kΩ were less than 5%.

Impedance Analysis of Layer Structured NBT–CBT Mixed Ceramics

1998 ◽  
Vol 12 (11) ◽  
pp. 433-441 ◽  
Author(s):  
P. S. Rama Sastry ◽  
T. Bhimasankaram ◽  
G. S. Kumar ◽  
G. Prasad
Keyword(s):  
Comparative Study ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Equivalent Circuits ◽  
Impedance Spectra ◽  
Ceramic System ◽  
Different Temperatures ◽  
Mixed Ceramics ◽  
Mixed Ceramic ◽  
Complex Impedance Spectra

Complex impedance spectra of ferroelectric mixed ceramic system ( Na 0.5 Bi 0.5)1-x Ca x Bi 4 Ti 4 O 15 with x=0, 0.1, 0.3, 0.5, 0.7 and 1 was studied as a function of frequency and temperature in the range 1 KHz to 10 MHz and 30°C to 620°C respectively. Equivalent circuits involving resistive and capacitive elements at different temperatures, activation energies of relaxations and conduction were evaluated using impedance plots. A comparative study of impedance and conductivity facilities an insight in understanding the electrical nature of these electroceramics.

Complex Impedance Spectroscopy of Bi-Substituted Yttrium Iron Garnet (YIG)

2007 ◽  
Vol 336-338 ◽  
pp. 709-711 ◽  
Author(s):  
Hong Jie Zhao ◽  
Ji Zhou ◽  
Zhi Lun Gui ◽  
Long Tu Li
Keyword(s):  
Grain Boundaries ◽  
Yttrium Iron Garnet ◽  
Complex Impedance ◽  
Physical Structure ◽  
Impedance Spectra ◽  
Yttrium Iron ◽  
Electrical Equivalent Circuit ◽  
Small Resistance ◽  
Iron Garnet ◽  
Complex Impedance Spectra

The effects of Bi-substitution on the complex impedance spectra of yttrium iron garnet (YIG) were studied in this paper. The polycrystalline yttrium iron garnet Y2BiFe5O12 (YIG: Bi) and Y3Fe5O12 (YIG) samples were prepared by solid-reaction method. The complex impedance spectra were measured in the frequency range from 1 KHz to 100MHz at several temperatures between 210oC and 500oC. The complex impedance sample shows that the YIG: Bi can be represented by double Cole-Cole semicircles, and the YIG can be represented by a single Cole semicircle. The physical structure of the specimen was visualized as comprising of small resistance grains separated by large resistance grain boundaries in accordance with the impedance spectra observations. The electrical processes in the sample were modeled in the form of an electrical equivalent circuit made up of a series combination of two parallel RC circuits attributed to grains and grain boundaries. The temperature dependence of bulk resistance indicated an evidence of Arrhenius-type thermally activated process, showing a close to linear variation up to a temperature of 740 K.

Dielectric Behavior of Mechano-chemically Synthesized [(CH3NH3)3Bi2Br9]: A Lead Free Hybrid Perovskite

2021 ◽  
Author(s):  
Swagatalaxmi Pujaru ◽  
Priyabrata Sadhukhan ◽  
Basudev Ghosh ◽  
Arup Dhara ◽  
Sachindranath Das
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Dielectric Behavior ◽  
Lead Free ◽  
Published Data ◽  
Temperature Dependent ◽  
Microstructural Parameters ◽  
Hybrid Perovskite ◽  
Refinement Method

Abstract Lead free hybrid halide perovskite (CH3NH3)3Bi2Br9 has been successfully synthesized by mechano-chemical method. The microstructure analysis by Rietveld’s refinement method revealed that the crystal belongs to trigonal system with space group P3 ̅m1. The obtained microstructural parameters are well in agreement with the previously published data. Temperature-dependent ac conductivity, impedance spectroscopy, and complex dielectric properties have been investigated in detail. The negative temperature coefficient of resistance behaviour reveals the semiconducting nature of the materials. The complex impedance spectroscopy also supports the semiconducting nature of the sample with activation energy for conduction ~0.38 eV.

Analysis of interface switching for Nb doped SrTiO3 single crystal device using complex impedance spectroscopy

2010 ◽  
Vol 10 (1) ◽  
pp. e68-e70 ◽  
Author(s):  
Joonmyoung Lee ◽  
El Mostafa Bourim ◽  
Dongku Shin ◽  
Jong-Sook Lee ◽  
Dong-jun Seong ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Single Crystal ◽  
Complex Impedance ◽  
Complex Impedance Spectroscopy

scholarly journals Switching dynamics of single and coupled VO2-based oscillators as elements of neural networks

2017 ◽  
Vol 31 (02) ◽  
pp. 1650261 ◽  
Author(s):  
Andrey Velichko ◽  
Maksim Belyaev ◽  
Vadim Putrolaynen ◽  
Alexander Pergament ◽  
Valentin Perminov
Keyword(s):  
Neural Networks ◽  
Strong Coupling ◽  
Capacitive Coupling ◽  
Chaotic Oscillations ◽  
Physical Mechanisms ◽  
Coupling Capacitance ◽  
Switching Dynamics ◽  
Proposed Model ◽  
Coupling Mode ◽  
Phase Differences

In the present paper, we report on the switching dynamics of both single and coupled VO2-based oscillators, with resistive and capacitive coupling, and explore the capability of their application in oscillatory neural networks. Based on these results, we further select an adequate SPICE model to describe the modes of operation of coupled oscillator circuits. Physical mechanisms influencing the time of forward and reverse electrical switching, that determine the applicability limits of the proposed model, are identified. For the resistive coupling, it is shown that synchronization takes place at a certain value of the coupling resistance, though it is unstable and a synchronization failure occurs periodically. For the capacitive coupling, two synchronization modes, with weak and strong coupling, are found. The transition between these modes is accompanied by chaotic oscillations. A decrease in the width of the spectrum harmonics in the weak-coupling mode, and its increase in the strong-coupling one, is detected. The dependences of frequencies and phase differences of the coupled oscillatory circuits on the coupling capacitance are found. Examples of operation of coupled VO2 oscillators as a central pattern generator are demonstrated.

Visualizing Impedance Spectroscopy Response for Interpretation of Collected Data

2021 ◽  
Vol 105 (1) ◽  
pp. 109-118
Author(s):  
Petr Vanysek
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Permittivity ◽  
Electrical Impedance ◽  
Complex Modulus ◽  
Physical Reality ◽  
Standard Part ◽  
In Series ◽  
As If

Measurements and interpretation of electrical impedance in electrochemistry and in related studies has become recently fairly commonplace as both the hardware and the interpretation software are more and more standard part of electrochemical potentiostats. With the interpretation software it is possible to model the studied system in any conceivable way, even if the physical reality may not follow the chosen model. An example is given where a circuit consisting of a capacitor with resistors in series and parallel are evaluated as if the circuit were just a pure capacitor. The method of plotting the results as complex permittivity and complex modulus is also shown.

Sign in / Sign up

Export Citation Format

Share Document