Electrical properties of new tin dioxide varistor ceramics at high currents

Lu, Zhenya; Glot, A.B.; Ivon, A.I.; Zhou, Ziyang

doi:10.1016/j.jeurceramsoc.2012.05.029

Cited by 12 publications

(4 citation statements)

References 29 publications

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“…At high enough applied voltage, a breakdown of these intergranular barriers takes place and the conductivity rapidly increases in a narrow range of the applied voltage. This characteristic constitutes the working principle of metal-oxide varistors, used as circuit protection [3][4][5][6][7][8]. Potential barriers are caused by intergrain states that may arise due to the presence of impurity or additive atoms, or to dislocations introduced by the crystallographic mismatch between adjacent grains, or because of an intergranular layer, which is another oxide.…”

Section: Introductionmentioning

confidence: 99%

Mild degradation processes in ZnO-based varistors: the role of Zn vacancies

Ponce

Macchi

Schipani

et al. 2015

Philosophical Magazine

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The effects of a degradation process on the structural and electrical properties of ZnO-based varistors induced by the application of dc bias voltage were analysed. Capacitance and resistance measurements were carried out to electrically characterize the polycrystalline semiconductor before and after different degrees of mild degradation. Vacancies' changes in the varistors were studied with positron annihilation lifetime spectroscopy. Variations on the potential barrier height and effective doping concentration were determined by fitting the experimental data from impedance spectroscopy measurements. These results indicate two different stages in the degradation process consistent with vacancy-like concentration changes.

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Section: Introductionmentioning

confidence: 99%

Mild degradation processes in ZnO-based varistors: the role of Zn vacancies

Ponce

Macchi

Schipani

et al. 2015

Philosophical Magazine

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“…In this case, we used the samples with small electrodes (area of 0.025 -0.04 cm 2 ) to obtain large values of current density. Techniques for creating small electrodes and studying the CVC at high currents are described in [6]. Oscillograms of voltage and current during pulse tests were recorded using a double-beam storage oscilloscope C8-11.…”

Section: Samples and Methods Of Investigationmentioning

confidence: 99%

Conductivity of grains in nonlinear oxide ceramics and protective properties of varistors

Ivon

Lavrov

2019

JPhysElectron

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The current-voltage characteristics of various compositions of nonlinear varistor ceramics based on ZnO (ZOC) and SnO2 (TOC) are studied in a wide range of electric current. On the basis of obtained data were determined the parameters that allow finding the coefficients kprs and kprl, which define the protection levels against the switching surge and the lightning surge for surge suppressors on the basis of ZOC and TOC varistors. The lower the value of these coefficients are, the significantly higher the efficiency of surge protection is. A relationship between kprs, kprl, and the effective linear resistivity ρlin limiting the current of intergranular barriers in varistor ceramics are established. It is shown that the values of kprs and kprl increase with increasing ρlin, which value is determined by the bulk resistance of the ceramic grains. The studied TOC compositions have 2-3 times larger values of ρlin and more high values of kprs and kprl than ZOC. ZOC-based varistors with lower kprs and kprl values provide more effective surge protection than TOC-based varistors.

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“…Also, the values of α are frequently estimated at this current density. Ceramic varistors based on zinc oxide (ZnO) are commercially available but at present tin dioxide (SnO 2 ) based varistors are intensively studied because they have electrical parameters comparable with parameters of ZnO varistors [2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%