Electrical properties and AC degradation characteristics of low voltage ZnO varistors doped with Nd2O3

2010 ◽  
Vol 36 (3) ◽  
pp. 1095-1099 ◽  
Author(s):  
Mao-hua Wang ◽  
Qing-hua Tang ◽  
Chao Yao
Keyword(s):  
Electrical Properties ◽  
Low Voltage ◽  
Zno Varistors

scholarly journals Microstructure and Electrical Properties of Low-Voltage Barium Titanate Doped Zinc Oxide Varistor Ceramics

2019 ◽  
Vol 8 (4) ◽  
pp. 2713-2718
Keyword(s):  
Zinc Oxide ◽  
Electrical Properties ◽  
Barium Titanate ◽  
Grain Boundary ◽  
Barrier Height ◽  
Current Density ◽  
Low Voltage ◽  
X Ray ◽  
Highly Nonlinear ◽  
Zno Varistors

In the present, varistor ceramics through the combination of zinc oxide (ZnO) with a perovskite material have become widespread because of their unique properties for a wide range of applications in electronic protection devices. Low-voltage zinc oxide (ZnO) varistors with fast response and highly nonlinear electrical properties for overvoltage protection in an integrated circuit are increasingly significant in the application of low-voltage electronics. The present study highlights the interaction between barium titanate (BaTiO3 ) and ZnO varistors through the employment of solid-state reaction method in the production of low-voltage varistors. The effects of BaTiO3 on the microstructure of ZnO varistors were analyzed through scanning electron microscopy (SEM), energy dispersive X-ray analysis spectroscopy (EDS) and X-ray diffraction (XRD). The EDS analysis and XRD measurements suggest the presence of ZnO and BaTiO3 phases. The electrical properties of BaTiO3 -doped ZnO varistors were examined based on the current density-electric field (J-E) characteristics measurement. The varistor properties showed the nonlinear coefficient (α) from 1.8 to 4.8 with the barrier height (φB) ranged from 0.70 to 0.88 eV. The used of BaTiO3 additive in ZnO varistors produced varistor voltages of 4.7 to 14.1 V/mm with the voltage per grain boundary (Vgb) was measured in the ranges 0.03 to 0.05 V. The lowest leakage current density was 348 µA/cm2 , obtained at the samples containing 12 wt.% BaTiO3 with high barrier height. The reduction in barrier height with increasing BaTiO3 content was associated with the excessive amount of BaTiO3 phase, hence cause the deterioration of active grain boundary due to the variation of oxygen (O) vacancies in the grain boundary.

scholarly journals Revisiting the effects of Co 2 O 3 on multiscale defect structures and relevant electrical properties in ZnO varistors

High Voltage ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Men Guo ◽  
Yao Wang ◽  
Kangning Wu ◽  
Lei Zhang ◽  
Xia Zhao ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Defect Structures ◽  
Zno Varistors

Effects of SiO2/Cr2O3 ratios on microstructures and electrical properties of high voltage gradient ZnO varistors

2019 ◽  
Vol 30 (13) ◽  
pp. 12113-12121 ◽  
Author(s):  
Xuejun Ruan ◽  
Xin Ren ◽  
Wenting Zhou ◽  
Xi Xu ◽  
Xin Wang ◽  
...  
Keyword(s):  
Electrical Properties ◽  
High Voltage ◽  
Voltage Gradient ◽  
Zno Varistors

ChemInform Abstract: Fabrication of Low-Voltage ZnO Varistors by a Two-Step Process.

ChemInform ◽  
2010 ◽  
Vol 26 (33) ◽  
pp. no-no
Author(s):  
J.-H. HAN ◽  
D.-H. LEE ◽  
D.-Y. KIM
Keyword(s):  
Low Voltage ◽  
Step Process ◽  
Zno Varistors

Electrical Properties of a TiO2-SrO Varistor System

2014 ◽  
Vol 975 ◽  
pp. 168-172
Author(s):  
Tiago Delbrücke ◽  
Igor Schmidt ◽  
Sergio Cava ◽  
Vânia Caldas Sousa
Keyword(s):  
Titanium Dioxide ◽  
Electrical Properties ◽  
Field Strength ◽  
Leakage Current ◽  
Low Voltage ◽  
Nonlinear Coefficient ◽  
Breakdown Field ◽  
Strontium Oxide ◽  
Breakdown Field Strength

The addition of different dopants affects the densification and electrical properties of TiO2 based varistor ceramics. The nonlinear current (I) and voltage (V) characteristics of titanium dioxide are examined when doped with small quantities (0.5-2 at.%) of strontium oxide. This paper discusses the electrical properties of such an SrO doped TiO2 system, and demonstrates that some combinations produce electrical properties suitable for use as low voltage varistors. The high value of the nonlinear coefficient (α) (6.6), the breakdown field strength (Eb) (328 V/cm) and the leakage current (Ir) (0.22 mA/cm2) obtained in a system newly doped with SrO, are all adequate properties for application in low voltage varistors.

scholarly journals From Non-Modular to Modular Concept of Bidirectional Buck/Boost Converter for Microgrid Applications

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3287
Author(s):  
Michal Frivaldsky ◽  
Slavomir Kascak ◽  
Jan Morgos ◽  
Michal Prazenica
Keyword(s):  
Electrical Properties ◽  
Low Voltage ◽  
Power Delivery ◽  
Switching Frequency ◽  
Modular Concept ◽  
Pros And Cons ◽  
Volume Output ◽  
Time Critical ◽  
System Volume ◽  
Current Ripple

In this article, the practical comparison of the operational performance of the modular (or multiport) and non-modular bidirectional buck/boost (bi-BB) DC/DC converter is realized. The main contribution of the work is the evaluation of both concepts based on various aspects, considering the qualitative indicators of the systems relevant for microgrids. Here, we discuss efficiency, electrical properties, costs, and component values. At the same time, critical comparisons are provided for converters based on SiC and GaN technology (non-modular high-voltage SiC-based dual-interleaved converter and modular low-voltage GaN-based). The concepts are specific with their operating frequency, whereby for each solution, the switching frequency is different and directly influences relevant components. The efficiency, overall system volume, output voltage ripple, and input current ripple are compared mutually between both concepts with a dependency on power delivery. These factors, together with overall volume and costs, are very important considering modern converters for microgrid systems. The summary of pros and cons is realized for each of the proposed converters, whereby the evaluation criterion is reflected within the electrical properties targeting microgrid application.

Electrical Properties of Microwave-Sintered ZnO Varistors

1999 ◽  
Vol 38 (Part 1, No. 9B) ◽  
pp. 5500-5504 ◽  
Author(s):  
Wan-Chui Lee ◽  
Kuo-Shung Liu ◽  
I-Nan Lin
Keyword(s):  
Electrical Properties ◽  
Zno Varistors

Effect of Technological Parameters on the Microstructure and Electrical Properties of ZnO Varistors

2013 ◽  
Vol 820 ◽  
pp. 208-211
Author(s):  
Li Li ◽  
Qi Bin Liu
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Leakage Current ◽  
Sintering Temperature ◽  
Voltage Gradient ◽  
Technological Parameters ◽  
Reaction Route ◽  
Conventional Solid State Reaction ◽  
Zno Varistors ◽  
Solid State Reaction Route

To improve voltage-gradient and to reduce the sintering temperature of ZnO varistors, high voltage-gradient ZnO varistors were synthesized with a conventional solid state reaction route. By means of SEM and DC parameter instrument for varistor, the influence of different technological parameters on microstructure, voltage-gradient and leakage current of ZnO varistors was investigated. The experimental results show that by using the process that presintering the additives at 850°C, the density is improved, the voltage-gradient is increased, and the leakage current is decreased. The optimum voltage-gradient and leakage current are 371V/mm and 3μA, respectively.

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