Results 191 to 200 of about 2,040 (221)
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ZnO varistors from intensively milled powders
Journal of the European Ceramic Society, 2007Abstract Two ways of application of intensive milling in ZnO varistors processing were compared. First was intensive milling of mixture of previously prepared constituent phases. In this case, intensive milling was applied only to obtain highly activated nanocrystalline varistor powder mixtures.
Zunic, M. +4 more
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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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Microwave Sintering of ZnO Varistor Ceramics
MRS Proceedings, 1992ABSTRACTZnO varistors are electronic ceramics whose electrical behavior is dominated by grain boundary effects. A careful evaluation of the effect of microwave sintering compared to conventional sintering revealed no significant differences between varistor devices processed by these two methods.
Lionel M. Levinson +2 more
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Electron paramagnetic resonance study of ZnO varistor material
Journal of Physics: Condensed Matter, 2014Matsuoka-type zinc oxide (ZnO) varistor material was synthesized using a conventional solid-state reaction method. X-band electron paramagnetic resonance (EPR) data revealed that Mn ions substitute in the ZnO lattice with a 2+ paramagnetic state. Co ions with either 3+ or 2+ oxidation states are only detectable at cryogenic temperatures.
Baraki, Raschid +4 more
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Electrically active interfaces in ZnO varistors
Solid State Ionics, 1995Abstract The chemical and electronic interface phenomena in doped ZnO ceramics are described. Monoatomic layers of excess bismuth and oxygen at the grain boundaries are responsible for the electrical activity of the interfaces. Characteristic bulk and interface defect levels govern the electrical behaviour.
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Analysis of ZnO varistors prepared from nanosize ZnO precursors
Materials Research Bulletin, 1998Abstract Varistors in the system ZnO–Bi 2 O 3 –Sb 2 O 3 –Co 2 O 3 –MnO 2 –Al 2 O 3 were fabricated from doped ZnO nanopowders prepared by a previously developed sol-gel process. The nanopowders were compacted under two different conditions and then conventionally sintered at 950°C for 2 h. Varistor samples with densities > 0.98 theoretical and grain
Kang Xue Ya +3 more
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Spinel Phases in ZnO Varistors
Physica Status Solidi (a), 1980K.-H. Bäther +4 more
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2020
ZnO VARI STORE WITH IRON OXIDE CAM, Ibrahim Faculty of Engineering Department of Metallurgical Engineering, M. S. Thesis Supervisor: Prof. Dr. Muharrem T1MUCÎN 114 pages, February 1989 ABSTRACT In the present work, addition of Fe2Û3 on the characteristics of ZnO-var istors were studied.
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ZnO VARI STORE WITH IRON OXIDE CAM, Ibrahim Faculty of Engineering Department of Metallurgical Engineering, M. S. Thesis Supervisor: Prof. Dr. Muharrem T1MUCÎN 114 pages, February 1989 ABSTRACT In the present work, addition of Fe2Û3 on the characteristics of ZnO-var istors were studied.
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Grain Boundary Phenomena in ZnO Varistors
MRS Proceedings, 1981ABSTRACTThe paper resumes essential grain boundary phenomena which were found experimentally by microcontact measurements on adjacent grains. The results suggest a ZnO homojunction model. Calculations of defect equilibria in the Schottky defect model show that homojunctions can be formed during the cooling period under the influence of an extrinsic ...
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Microscopic degradation model for ZnO varistors
Physica Status Solidi (a), 1983K.-H. Bätheb +3 more
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