Results 161 to 170 of about 2,258 (200)
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Journal of the American Ceramic Society, 1987
The varistor properties were examined in porous ZnO. The sample used contained no dopants such as Bi 2 O 3 or Pr 6 O 11 , which are usually considered to be useful in ...
Satoru Fujitsu +2 more
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The varistor properties were examined in porous ZnO. The sample used contained no dopants such as Bi 2 O 3 or Pr 6 O 11 , which are usually considered to be useful in ...
Satoru Fujitsu +2 more
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Journal of Physics: Condensed Matter, 1993
Among the mechanisms suggested to account for degradation of varistor materials, ion migration has strong support. Mobile, positively charged ions in the depletion layer would be the key element in degradation. In this context, the authors discuss the consequences of an electrical stressing on the current-temperature characteristic of a comment ...
M S Castro, M A Benavente, C M Aldao
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Among the mechanisms suggested to account for degradation of varistor materials, ion migration has strong support. Mobile, positively charged ions in the depletion layer would be the key element in degradation. In this context, the authors discuss the consequences of an electrical stressing on the current-temperature characteristic of a comment ...
M S Castro, M A Benavente, C M Aldao
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Thermal breakdown in ZnO-varistor ceramics
Physica Status Solidi (a), 1980Thermal breakdowns representing an essential mechanism for the lifetime limitation of ZnO-varistor ceramics are characterized with respect to the parameters of the breakdown point (especially breakdown temperature Tb) (for 21 °C as ambient temperature: Tb = 174 °C).
W. Brückner, W . Moldenhauer, D. Hinz
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Failure modelling for ZnO varistors
Journal of Materials Processing Technology, 1998Abstract The energy-absorption capability of zinc oxide varistors depends on both the binder burn-out and shrinkage rate of the disc. This paper presents a study of the development of a failure model of a varistor disc with a nominal voltage V nom =5 kV and a diameter of 42 mm manufactured by rate-controlled sintering.
M.D Huda +3 more
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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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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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Photoconduction of ZnO-Bi2O3 varistors
Journal of Materials Science Letters, 1989Zinc oxide (ZnO) ceramics with a few mol % Bi203, CoO, MnO, Sb203, etc., as additives exhibit a high non-ohmic property in their voltage-current characteristics [1, 2], and therefore they are called varistors and are widely used for surge protection against transient voltage and powder overload [3].
T. Sekiya +3 more
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High-field ZnO-based varistors
Journal of Physics D: Applied Physics, 1995The role of principal additives is investigated in an attempt to obtain high-threshold-field ZnO-based varistors in the traditional way. In the order of effect level, these are Sb2O3, Co3O4, Cr2O3 and MnO2. In the range of 0.5-5 mol%, the increase of additive content decreases the average ZnO grain size.
A Bui, H T Nguyen, A Loubiere
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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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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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