Journal ArticleDOI
Grain growth control in ZnO varistors using seed grains
TLDR
In this paper, a method for making lowvoltage ZnO varistors having extraordinarily large grain size without necessity of sintering at much higher temperatures or for much longer times is reported.Abstract:
A method for making low‐voltage ZnO varistors having extraordinarily large grain size without necessity of sintering at much higher temperatures or for much longer times is reported. The device is made by sintering a mixture of ZnO fine powder, additives, and ZnO seed grains having grain sizes of 63–105 μm obtained by washing a ZnO sintered body containing BaO in boiling water. The device has a grain size around 500 μm and low threshold voltage of 6 V/mm. Such anomalous grain growth is caused by the difference between the radii of curvature of ZnO fine powder and ZnO seed grains.read more
Citations
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Journal ArticleDOI
Control of Liquid‐Phase‐Enhanced Discontinuous Grain Growth in Barium Titanate
TL;DR: The titanate de baryum present a croissance de grain discontinue en presence of petites quantites de l'eutectique liquide Ba 6 Ti 17 O 40 −BaTiO 3 a T>1312°C as mentioned in this paper.
Journal ArticleDOI
Effect of Bi2O3 addition on the microstructure and electrical properties of the SnO2.CoO.Nb2O5 varistor system
TL;DR: In this article, it was shown that the CoO and Nb2O5 doped SnO2 ceramic is single phase and presents varistor behaviour with AE 8.0.
Journal ArticleDOI
Different ‘‘single grain junctions’’ within a ZnO varistor
TL;DR: The experimental part of this paper describes a new method to determine the electrical characteristics of a single ZnO varistor grain-to-grain junction as mentioned in this paper, which is described in statistical terms because each single barrier has been found to present its own electrical characteristics.
Journal ArticleDOI
Processing of textured zinc oxide varistors via templated grain growth
Ender Suvaci,I. Özgür Özer +1 more
TL;DR: In this paper, Rod-like, anisotropic ZnO particles (templates) were synthesized by homogeneous precipitation method and aligned zinc oxide templates were aligned in such a position where c-axes of the templates are parallel to the tape casting direction during the modified tape casting process.
Journal ArticleDOI
Effect of variations in grain size and grain boundary barrier heights on the current-voltage characteristics of ZnO varistors
Ce-Wen Nan,David R. Clarke +1 more
TL;DR: In this article, a multibond percolation approach utilizing effective medium theory was proposed to calculate the effect of microstructural variations on the overall electrical transport properties of ZnO grains.
References
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Book
Introduction to Ceramics
TL;DR: In this paper, the authors present a model for the development of the MICROSTRUCTURE in CERAMICS based on phase transformation, glass formation and glass-Ceramics.
Journal ArticleDOI
Nonohmic Properties of Zinc Oxide Ceramics
TL;DR: In this paper, the non-ohmic properties of ZnO ceramics with five additives of Bi2O3, CoO, MnO, Cr2O 3, and Sb 2O3 are studied in relation to sintering temperature, additive content, and temperature dependence.
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Formation Mechanism of Nonohmic Zinc Oxide Ceramics
TL;DR: For the formation of non-ohmic ZnO ceramics, Oxide additives markedly influence these reactions and consequently the phases and microstructure dissolving into the above phases and relating to composition and sintering conditions as discussed by the authors.
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Sintering and varistor characteristics of ZnO‐Bi2O3 ceramics
TL;DR: In this paper, the sintering behavior of binary ZnO ceramics (containing 0.01-1 mol% of added Bi2O3) was investigated and it was shown that densification in the initial stage of sinter, and grain growth of the ZnOs matrix are enhanced in the presence of a liquid Bi 2O3 phase.
Journal ArticleDOI
Low voltage ZnO varistor: Device process and defect model
TL;DR: In this paper, a defect model which takes into account the role of oxygen in developing the nonlinear behavior of a ZnO varistor with a breakdown voltage less than 20 V is presented.