Results 141 to 150 of about 215,655 (219)
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, 2020
In present study, impact of CaO doping on microstructure and phase electrical properties of a ZnO varistor is being reported. The doped ZnO nanopowders were prepared by solution combustion followed by conventional sintering.
K. Hembram +4 more
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In present study, impact of CaO doping on microstructure and phase electrical properties of a ZnO varistor is being reported. The doped ZnO nanopowders were prepared by solution combustion followed by conventional sintering.
K. Hembram +4 more
semanticscholar +1 more source
The microstructure of a ZnO varistor material
Journal of Materials Science, 1985The microstructure of a ZnO varistor material has been investigated by a combination of X-ray diffractometry and analytical electron microscopy (SEM, TEM, STEM, EDX). The material was found to consist of: ZnO grains (doped with manganese, cobalt and nickel); smaller spinel grains which hinder the growth of ZnO grains during sintering; intergranular Bi ...
E. Olsson +3 more
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IEEE Transactions on Instrumentation and Measurement
The implementation of online monitoring and intelligent diagnosis method for the surge arrester can enhance the supervision of its full lifecycle status, thereby further improving the safe and reliable operation of the power grid.
Jianfeng Shi +8 more
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The implementation of online monitoring and intelligent diagnosis method for the surge arrester can enhance the supervision of its full lifecycle status, thereby further improving the safe and reliable operation of the power grid.
Jianfeng Shi +8 more
semanticscholar +1 more source
A barrier model for ZnO varistors
Journal of Applied Physics, 1979A model of current transport in ZnO varistors is proposed. The model is a modification of an earlier one suggested by Levine, with the major difference being the inclusion of a thin (?10 Å) ’’disordered’’ layer which separates the single-crystal ZnO grains.
P. L. Hower, T. K. Gupta
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Phase development in ZnO varistors
Advances in Applied Ceramics, 2015Based on a typical ZnO varistor composition (97·0 mol.-% ZnO, 1·0 mol.-% Bi2O3, 1·0 mol.-% Sb2O3, 0·5 mol.-% MnO and 0·5 mol.-% Co3O4), phase development of the ZnO varistor during sintering has been investigated using in situ high temperature X-ray diffraction up to 900°C, and conventional ambient X-ray diffraction for samples sintered at 900°C to ...
Ji-wei Fan, P. Poosimma, Robert Freer
semanticscholar +3 more sources
Theory of conduction in ZnO varistors
Journal of Applied Physics, 1979A theory is presented which quantitatively accounts for the important features of conduction in ZnO-based metal-oxide varistors. This theory has no adjustable parameters. Using the known values of the ZnO band gap, donor concentration n0, and low-voltage varistor leakage-current activation energy, we predict a varistor breakdown voltage of ?3.2 V/grain
G. D. Mahan +2 more
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Investigation of dielectric relaxation and degradation behavior of two-step sintered ZnO varistors
Ceramics International, 2019In this study, ZnO varistors using sub-micron varistor powders by two-step sintering were fabricated in contrast to conventional sintering. The microstructures, electrical properties, and the degradation behavior under a severe dc electric field and a ...
Zhiyao Fu +4 more
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Conduction mechanisms in ZnO varistors
Journal of Applied Physics, 1980The thermionic emission enhanced by barrier lowering and the Zener tunnelling in ZnO varistors are discussed. Capacitance versus voltage, reverse current versus temperature, and 1/f noise measurements have been performed on commercial varistors. A model is proposed from which follows a diffusion voltage VD which is consistent both with the 1/C2 vs V ...
L. K. J. Vanadamme, J. C. Brugman
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ZnO Varistors for Transient Protection
IEEE Transactions on Parts, Hybrids, and Packaging, 1977ZnO varistors are novel ceramic semiconductor devices used for protection of electronic equipment against transient overvoltages due to switching surges or lightning. This article describes the microstructure, circuit behavior, and operation of ZnO varistors.
L. Levinson, H. Philipp
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Mesoscopic modeling of the mechanically tunable electrical conductivity of ZnO varistors
, 2020An electromechanically coupled model for the simulation of electric current flow in ZnO varistors is presented. The model is based on an equivalent circuit representation of the varistor microstructure, where the grain boundaries are modeled as nonlinear
K. A. Taylor, E. Gjonaj, Z. Zhou, B. Xu
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