Nonlinearity Characteristics of Low-Voltage Barium Titanate Based Zinc Oxide Varistor Ceramics Modified by Cobalt Dopants

Synthesis of Barium-zinc-titanate Ceramics

Mixtures of BaCO3, ZnO and TiO2 powders, with molar ratio of 1:2:4, were mechanically activated for 20, 40 and minutes in a planetary ball mill. The resulting powders were compacted into pellets and isothermally sintered at 1250 °C for 2h with a heating rate of 10 °C/min. X-ray diffraction analysis of obtained powders and sintered samples was performed in order to investigate changes of the pha...

Synthesis Mechanism of Low-Voltage Praseodymium Oxide Doped Zinc Oxide Varistor Ceramics Prepared Through Modified Citrate Gel Coating

High demands on low-voltage electronics have increased the need for zinc oxide (ZnO) varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synth...

Metal Oxide ZnO-Based Varistor Ceramics

Model for zinc oxide varistor

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...

Dc and Ac Electrical Properties of Ptc Barium Titanate Ceramics

The dc and ac electrical properties of PTC barium titanate ceramics were measured in the temperature range from 30 to 450°C. The Heywang's model alone is not sufficient to perform a quantitative analysis of the results. The heterogeneity of the system is taken into account.