Zinc oxide varistors are very complex systems, and the dominant mechanism of voltage barrier formation in these systems has not been well established. Yet the MNDO quantum mechanical theoretical calculation was used in this work to determine the most probable defect type at the surface of a ZnO cluster. The proposed model represents well the semiconducting nature as well as the defects at the Z...

The article is devoted to the study of relationship between electrical characteristics and microstructure varistor. C-V varistors from 10 manufacturers represented in Russian Federation were experimentally determined. To compare parameters samples, dependences "electric field-conductivity" (E-σ) built out, coefficients nonlinearity metal oxide their chemical composition studied. As a result sta...

Neither the effects of repetitive swells on metal-oxide varistors, nor the natural occurrence of swells had been documented in the literature. The paper briefly described a laboratory system capable of generating arbitrary swells and applying them to test varistors. A statistical experiment on five lots of varistors was performed and preliminary results reported. Effects of amplitude, duration,...

A stability loss of varistor is subjected to any variety extreme conditions such different stresses AC or DC, temperature, pulse, pressure, humidity, etc. This causes degradation phenomenon and leads thermal runaway failure varistor. The investigation phenomena an important subject for prolonging their lives. In this study, we investigate the process ZnO 1-x -CoO 2.0 -SLS x ceramics where x= 0....

ZnO-based varistors protect electronic circuits against overvoltage. High temperature from the range of 1150–1300 C is required for proper sintering of such material. Varistor inks with lower firing temperature are needed for application in thick-film and LTCC technology. ZnO-based thick-film composition was prepared and varistors were fabricated on alumina and LTCC substrate. Different topolog...

In ZnO-based low voltage varistor, the two essential features of microstructure determining its nonlinear response are the formation Bi-enriched active grain boundaries as well as a controlled ZnO grain size by secondary spinel-type phases. Besides, the microstructure and phase composition are strongly affected by the dopant concentration during sintering process. In this study, the optimal dop...