Results 151 to 160 of about 215,655 (219)
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MRS Proceedings, 1981
The theory of ZnO varistors has evolved along with the increasingly detailed experimental description [1-2]. The extreme nonlinearity in the currentvoltage curves naturally led the early investigators to suggest the well-known nonlinear mechanisms, such as space-charge limited currents or electron tunneling. Later experiments made these first proposals
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The theory of ZnO varistors has evolved along with the increasingly detailed experimental description [1-2]. The extreme nonlinearity in the currentvoltage curves naturally led the early investigators to suggest the well-known nonlinear mechanisms, such as space-charge limited currents or electron tunneling. Later experiments made these first proposals
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Synthesis and characterization of multilayered ZnO/glass/ZnO varistors
AIP Conference Proceedings, 2020Low-voltage surge filters are technologically important for the protection of modern computing and telecommunication systems operating at low voltages. In this context the design and characterization of varistors operating at low voltages constitutes a continuous challenge.
Varsamis, C. P. E. +3 more
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Breakdown phenomenon of ZnO varistors caused by non-uniform distribution of internal pores
, 2019Here, we analyzed the internal structure of ZnO varistors with X-ray micro-CT technology and showed that the porosity and pore volume at the radial edge is considerably higher than at other regions.
Pengfei Meng +7 more
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The influence of surfactant on ZnO varistors
Ceramics International, 2007Abstract ZnO varistors with and without surfactant such as sodium dodecyl sulphate (SDS) are prepared by nitrate-combustion process. The samples were identically heat treated and sintered at 1000 °C for 12 h to study the influence of the surfactant on the nonlinear electrical properties of polycrystalline ZnO.
S.R. Dhage, S.C. Navale, V. Ravi
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Defects and degradation in ZnO varistor
Applied Physics Letters, 1996A systematic study of the defects in ZnO has been performed. The two commonly observed levels (L1, L2), located at around 0.15 and 0.24 eV under the conduction band, have been identified as native defects. The deep level transient spectroscopy depth profiling technique is applied on multilayer-chip-type ZnO varistors to determine the distribution ...
Wei-I Lee, Ruey-Ling Young
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Prebreakdown Conduction in ZnO Varistors
Journal of the American Ceramic Society, 1992A model which quantitatively accounts for the important features of prebreakdown conduction in ZnO‐based metal oxide varistors in presented. The prebreakdown current dependence with applied voltage and temperature enables us to extract several features for the grain boundary.
Miriam S. Castro +3 more
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Impulse current withstanding capability of ZnO varistors with influence of varistor size
IEEJ Transactions on Electrical and Electronic Engineering, 2019Through injecting 8/20 and 30/60 μs impulse currents to five kinds of ZnO varistors, the influence of the varistor size on the single impulse current withstanding capability of a ZnO varistor is investigated in this article. A comprehensive damage criterion of a varistor consisting of three aspects, namely, mechanical failure by visual inspection ...
Jianguo Wang +5 more
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Varistor-capacitor characteristics of ZnO ceramics
Journal of Materials Science, 1986Electrical properties of ZnO ceramics quenched from several temperatures during the cooling down from sintering temperature were correlated with microstructural changes. Barrier parameters were determined and their variation was interpreted under the assumption that measured donor densities were due to extrinsic donor defects segregated at grain ...
P. Q. Mantas +2 more
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Metastable Barrier Voltage in ZnO Varistors
MRS Proceedings, 1981ABSTRACTA reversible change in barrier voltage is observed in assintered ZnO varistors upon application and removal of the applied voltage. This is attributed to a metastable component in the grain boundary Schottky barriers. Varistors show improved stability when the metastable component is removed or fixed by heat treatment.
Tapan K. Gupta +2 more
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Ceramic varistors based on ZnO–SnO2
Journal of the European Ceramic Society, 2004Abstract Model ceramic varistor formulations based on 98% ZnO–SnO2 (plus 2% oxides of Bi, Co and Mn) were prepared by conventional powder processing routes; specimens were sintered at 1150–1275 °C. The product density increased with SnO2 content, but decreased with increase in sintering temperature.
A. Anastasiou +3 more
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