Results 181 to 190 of about 968 (215)

Intrinsic defects in ZnO varistors

Journal of Applied Physics, 1983
Theoretical calculations are presented for equilibrium concentrations of zinc and oxygen vacancies in ZnO. Results are presented at the sintering temperature, and also at room temperature. Theoretical calculations of reaction constants show that the intrinsic donor is the oxygen vacancy, rather than the zinc interstitial.
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Cooling rate effects in ZnO varistors

Journal of Materials Science: Materials in Electronics, 1992
Cooling rate effects on ZnO-Bi2O3 varistors are presented. In particular, the oxygen vacancies (V o + ) concentration was determined by electron paramagnetic resonance (EPR) spectroscopy and related to the conductivity. It was found that a higher cooling rate provokes an increase of the V
M. S. Castro, L. Perissinotti, C. M. Aldao   +2 more
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Evaluation of ZnO Varistors by Photoacoustic Spectroscopy

Japanese Journal of Applied Physics, 2001
ZnO varistors degraded under various conditions were evaluated by photoacoustic spectroscopy (PAS). The degradation where the grain boundary is damaged by DC bias stress is more than that by AC bias stress. PAS, however, reveals that the interior of the grains of the sample degraded by AC bias stress is much more damaged than that by the DC bias ...
Yasuhiro Ohbuchi Yasuhiro Ohbuchi, Akitsugu Kimura Akitsugu Kimura, Toshio Kawahara Toshio Kawahara, Jun Morimoto Jun Morimoto, Taro Toyoda Taro Toyoda   +4 more
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High-field ZnO-based varistors

Journal of Physics D: Applied Physics, 1995
The 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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Spinel Phases in ZnO Varistors

Physica Status Solidi (a), 1980
K.-H. Bäther, D. Hinz, N. Mattern, M. Bitterlich, W. Brückner   +4 more
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Grain junction properties of ZnO varistors

Applications of Surface Science, 1979
Abstract Grain-grain junctions in ZnO varistor ceramics were electrically contacted by conventional photoresist- and contact deposition techniques and investigated in terms of the statistical distribution of the breakdown voltage. Its maximum appears at 3.4 V for constant current of 5 μA.
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ZnO varistors with iron oxide

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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Microscopic degradation model for ZnO varistors

Physica Status Solidi (a), 1983
K.-H. Bätheb, W. Brückner, W. Moldenhauer, H.-P. Brückner   +3 more
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Heat Conductivity in ZnO Varistor Ceramics

physica status solidi (a), 1982
W. Brückner, S. Lehmann, G. Pompe
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Observation of an electrical breakdown at ZnO Schottky contacts in varistors

Journal of the European Ceramic Society, 2021
Benjamin Kaufmann, Peter Supancic
exaly