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Enhanced time response and temperature sensing behavior of thermistor using Zn-doped CaTiO_3 nanoparticles

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Journal of Advanced Ceramics 2018年第2期7卷 99-108页

作者： Subhanarayan SAHOO Department of Electrical Engineering Adani Institute of Infrastructure Engineering

In the present study, Zn-doped CaTiO_3 nanocrystalline was synthesized to study the thermistor behavior with temperature. The X-ray powder diffraction analysis showed the formation of a single-phase orthorhombic structure at room temperature. The electrical resistance of the Zn-doped CaTiO_3 increased with increasing doping concentration and decreased at higher measuring temperature, showing a negative temperature coefficient of resistance(NTCR) behavior. Different thermistor parameters were calculated using Steinhart–Hart equations, whilst time domain analysis confirmed faster response towards applied voltage.

关键词： multiferroic X-ray diffraction (XRD) electrical properties conductivity impedance spectroscopy NTCR thermistor

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Complex impedance and electric modulus studies of magnetic ceramic Ni_(0.27)Cu_(0.10)Zn_(0.63)Fe_(2)O_(4)

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Journal of Advanced Ceramics 2015年第3期4卷 217-225页

作者： M.BELAL HOSSEN A.K.M.AKTHER HOSSAIN Department of Physics Chittagong University of Engineering and TechnologyChittagongBangladesh Department of Physics Bangladesh University of Engineering and TechnologyDhakaBangladesh

The electrical properties of Ni_(0.27)Cu_(0.10)Zn_(0.63)Fe_(2)O_(4)(NCZF)prepared from auto combustion synthesis of ferrite powders have been studied by impedance and modulus *** studied frequency and temperature dependencies of impedance and electric modulus of NCZF in a wide frequency range(20 Hz-5 MHz)at different measuring temperatures T_(SM)(30-225℃).The complex impedance spectra clearly showed both grain and grain boundary effects on the electrical *** observed impedance spectra indicated that the magnitude of grain boundary resistance R_(gb) becomes more prominent compared to grain resistance R_(b) at room temperature,and with the increase in T_(SM),R_(gb) decreases faster than the intrinsic R_(b).The frequency response of the imaginary part of impedance showed relaxation behavior at every T_(SM),and the relaxation frequency variation with T_(SM) appeared to be of Arrhenius nature and the activation energy has been estimated to be 0.37 eV.A complex modulus spectrum was used to understand the mechanism of the electrical transport process,which indicated that a non-Debye type of conductivity relaxation characterizes this material.

关键词： ferrimagnetic ceramics impedance spectroscopy electric modulus temperature dependence

Electrical properties of Na_(2)Pb_(2)R_(2)W_(2)Ti_(4)V_(4)O_(30)(R=Dy,Pr)ceramics

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Journal of Advanced Ceramics 2013年第2期2卷 112-118页

作者： Piyush R.DAS B.N.PARIDA R.PADHEE R.N.P.CHOUDHARY Department of Physics Institute of Technical Education&ResearchSiksha‘O’Anusandahan UniversityKhandagiriBhubaneswar 751030OdishaIndia

The polycrystalline samples of complex tungsten bronze(TB)Na_(2)Pb_(2)R_(2)W_(2)Ti_(4)V_(4)O_(30)(R=Dy,Pr)compounds were prepared by solid-state reaction ***-temperature preliminary structural studies confirm the formation of the compounds in the orthorhombic crystal *** studies of electrical properties of the materials using complex impedance spectroscopy technique exhibit that the impedance and related parameters are strongly dependent upon temperature and microstructure(bulk,grain boundary,etc).An observation of negative temperature coefficient of resistance(NTCR)suggests the materials have semiconducting *** variation of AC conductivity with temperature shows a typical Arrhenius behavior of the *** the samples obey Jonscher’s universal power *** existence of hopping mechanism in the electrical transport processes in the system with non-exponential type of conductivity relaxation is confirmed by electrical modulus analysis.

关键词： ceramics impedance spectroscopy electrical properties ferroelectricity microstructure

The electrical impedance, AC conductivity and dielectric properties of phenol red compound investigated and modeled by an artificial neural network

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Communications in Theoretical Physics 2020年第10期72卷 139-148页

作者： H A M Ali D M Habashy Physics Department Faculty of EducationAin Shams UniversityRoxyCairo 11757Egypt

The impedance spectroscopy,electrical conductivity and electric modulus of bulk phenol red were measured,as a function of both frequency and *** neural networks(ANNs)were used for modeling its electrical *** two parts(real and imaginary)of its complex impedance(Z^*)were analyzed and the activation energy related to the electrical relaxation process was *** curves were plotted showing semicircles for the different *** AC electrical conductivity follows a power lawσac(ω)αω^η.The maximum barrier height Bm was derived for specific temperatures.A plausible mechanism for the AC conduction of bulk phenol red was deduced from the temperature reliance of the frequency *** dielectric data was analyzed using electric modulus as a *** addition,ANNs were used to model the impedance parts and the total electrical *** runs were tried,to obtain the best *** training and prediction results were compared to the equivalent experimental results,with a good match *** equation describing the experimental results was obtained mathematically,based on the use of *** outputs demonstrated that ANNs are an admirable tool for modeling experimental results.

关键词： phenol red impedance spectroscopy electric modulus neural network

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On the Criteria of Instability for Electrochemical Systems

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Chinese Journal of Chemistry 2002年第7期20卷 657-662页

作者：李则林任斌牛振江肖小明曾跃田中群 Institute of Physical Chemistry Zhejiang Normal University Jinhua Zhejiang 321004 China Department of Chemistry Hunan Normal University Changsha Hunan 410081 China State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of Chemistry Xiamen University Xiamen Fujian 361005 China

Both cyclic-voltammetry-based and impedance-based experimental criteria thathave been developed recently for the oscil-latory electrochemical systems are critically appraisedwith two typical categories of oscillators. Consistent conclusions can be drawn by the two criteriafor the category of oscillators that involve the coupling of charge transfer mainly with surfacesteps (e.g. ad- and desorption) such as in the electrooxidation of C_1 organic molecules. Whereas,impedance-based criterion is not applicable to the category of oscillators that involve the couplingof charge transfer mainly with mass transfer (e.g. diffusion and convection) such as in theFe(CN)_6^(3-) reduction accompanying periodic hydrogen evolution. The reason is that the negativeimpedance cannot include the feedback information of convection mass transfer induced by thehydrogen evolution. However, both positive and negative nonlinear feedbacks, i. e., thediffusion-limited depletion and convection-enhanced replenishment of the Fe(CN)_6^(3-) surfaceconcentration, that coexist between the bistability, i. e., Fe(CN)_6^(3-) reduction with and withouthydrogen evolution at lower and higher potential sides respectively, are all reflected in thecrossed cyclic voltammo-gram (CCV). It can be concluded that the voltammetry-based criterion (intime domain) is more intuitive, less time-consuming and has a wider range of applications than theimpedance-based one (in frequency domain).

关键词： electrochemical oscillations criteria for instability cyclic voltammograms impedance spectroscopy C_1 organic molecules ferricyanide

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Effect of Li^(+)ion mobility on the grain boundary conductivity of Li_(2)TiO_(3) nanoceramics

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Journal of Advanced Ceramics 2014年第2期3卷 98-108页

作者： Umasankar DASH Subhanarayan SAHOO S.K.S.PARASHAR Paritosh CHAUDHURI School of Applied Sciences KIIT University Bhubaneswar-751024India Department of Electrical and Electronics Engineering Trident Academy of TechnologyBhubaneswar-751024India Institute for Plasma Research BhatGandhinagarGujurat-382428India

Lithium titanate(Li_(2)TiO_(3))is one of the most promising candidates among the tritium breeding materials because of its good tritium release *** concentration has much significance on the diffusivity of tritium in the *** nanocrystalline single-phase Li_(2)TiO_(3) with monoclinic structure has been prepared by high energy ball milling followed by calcination at 700℃for 2 *** field emission scanning electron microscopy(FESEM)studies confirmed uniform distribution of nanocrystalline phase with particle size below 100 *** study of the Li^(+)ion diffusion on the sintered sample was investigated by means of electrical conductivity *** properties of the samples were studied in wide temperature(50-500℃)and frequency(100 Hz-1 MHz)*** complex impedance spectroscopy(CIS)studies showed the presence of both bulk and grain boundary effects in nanocrystalline Li_(2)TiO_(3).The bulk resistance of the samples has been observed to decrease with rise in temperature showing a typical negative temperature coefficient of resistance(NTCR)*** low activation energies of the samples suggested the presence of singly ionized oxygen vacancies in the conduction *** hopping frequency shifted toward higher frequency with increase in *** energy of 0.86 eV was calculated from AC conductivity.

关键词： high energy ball milling AC conductivity impedance spectroscopy nanocrystalline

Frequency and temperature dependent electrical characteristics of CaTiO_(3) nano-ceramic prepared by high-energy ball milling

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Journal of Advanced Ceramics 2013年第3期2卷 291-300页

作者： Subhanarayan SAHOO Umasankar DASH S.K.S.PARASHAR S.M.ALI School of Electrical Engineering KIIT UniversityBhubaneswar 751024India Center for Nanotechnology KIIT UniversityBhubaneswar 751024India School of Applied Sciences KIIT UniversityBhubaneswar 751024India

Nanocrystalline calcium titanate(CT)ceramic has been synthesized by a combination of solid-state reaction and high-energy ball *** nano-ceramic is characterized by X-ray diffraction(XRD),dielectric study and impedance *** XRD pattern shows single phase ceramic of orthorhombic *** frequency-dependent dielectric study shows that the dielectric constant is maximized at low frequencies and decreases with an increase in *** spectroscopy analyses reveal a non-Debye type relaxation phenomenon.A significant shift in impedance loss peaks toward the higher-frequency side indicates conduction in the material favoring the long-range motion of mobile charge *** grain conduction effect is observed from the complex impedance spectrum by the appearance of one semicircular arc in Nyquist *** is also observed that the resistance decreases with an increase in temperature showing a negative temperature coefficient of resistance(NTCR).Various thermistor parameters have been calculated by fitting with Steinhart-Hart *** modulus plots represent the presence of temperature-dependent electrical relaxation phenomenon with the *** frequency-dependent AC conductivity at different temperatures indicates that the conduction process is thermally *** activation energy has been calculated from an Arrhenius plot of DC conductivity and relaxation frequency.

关键词： high-energy ball milling dielectric study impedance spectroscopy thermistor conductivity

Structural,dielectric and electrical properties of bismuth magnesium tantalate electronic system

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Journal of Magnesium and Alloys 2019年第4期7卷 628-636页

作者： Sarbasri Halder Satyanarayan Bhuyan R.N.P.Choudhary Department of Electronics and Communication Engineering Siksha‘O’AnusandhanDeemed to be UniversityBhubaneswar 751030India Department of Physics Siksha‘O’AnusandhanDeemed to be UniversityBhubaneswar 751030India

The lead-free dielectric compound Bi(Mg2/3Ta1/3)O3(BMT)has been synthesized at high temperature by a low-cost solid-state *** X-ray diffraction(XRD)technique reveals that the fabricated sample has an orthorhombic crystal *** scanning electron microscope(SEM)image displays the uniform distribution of grains on the surface of the *** dielectric parameters(permittivity(εr),and loss tangent(tanδ)are studied over a wide range of temperature(150-500℃)and frequency(1 kHz-1 MHz).The temperature dependent conductivity plot follows Universal Johnson’s power *** complex impedance and modulus spectrum illustrate the electrical behavior of the compound at various frequency and *** Nyquist spectra show the presence of the effect of grain and grain boundary in the synthesized *** grain resistance value declines with the rise in temperature that shows the presence of a negative temperature coefficient(NTCR)behavior in the *** complex modulus spectra display the occurrence of the conduction mechanism in the *** reported compound has a relative dielectric constant and loss of 22×10^3 and 1.8 respectively at 1 kHz frequency and 500℃,thus becoming an efficient applicant for dielectric applications that can operate at higher temperatures.

关键词： XRD impedance spectroscopy Conductivity Conduction

Monitoring concept for structural integration of PZT-fiber arrays in metal sheets:a numerical and experimental study

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International Journal of Smart and Nano Materials 2018年第1期9卷 56-67,I0003页

作者： Welf-Guntram Drossel Andreas Schubert Matthias Putz Hans-Joachim Koriath Volker Wittstock Sebastian Hensel Alexander Pierer Benedikt Müller Marek Schmidt Fraunhofer Institute for Machine Tools and Forming Technology ChemnitzGermany Professorship for Adaptronics and Lightweight Design Chemnitz University of TechnologyChemnitzGermany Professorship Micromanufacturing Technology Chemnitz University of TechnologyChemnitzGermany Professorship for Machine Tools and Forming Technology Chemnitz University of TechnologyChemnitzGermany

The technique joining by forming allows the structural integration of piezoceramic fibers into locally microstructured metal sheets without any elastic interlayers.A high-volume production of the joining partners causes in statistical deviations from the nominal dimensions.A numerical simulation on geometric process sensitivity shows that the deviations have a high significant influence on the resulting fiber stresses after the joining by forming operation and demonstrate the necessity of a monitoring *** this basis,the electromechanical behavior of piezoceramic array transducers is investigated experimentally before,during and after the joining *** piezoceramic array transducer consists of an arrangement of five electrical interconnected piezoceramic *** findings show that the impedance spectrum depends on the fiber stresses and can be used for in-process monitoring during the joining *** on the impedance values the preload state of the interconnected piezoceramic fibers can be specifically controlled and a fiber overload.

关键词： impedance spectroscopy joining by forming process monitoring function integration sensitivity