Microstructure Design and Optimization of ZnO-Bi2O3-Sb2O3 Based Ceramic Varistors

2012 ◽  
Vol 519 ◽  
pp. 232-235
Author(s):  
Cheng Peng ◽  
Dan Xie ◽  
Tian Ling Ren ◽  
Zhi Jian Peng
Keyword(s):  
Electrical Properties ◽  
Leakage Current ◽  
Sintering Temperature ◽  
Nonlinear Coefficient ◽  
Electrical Performance ◽  
Microstructure Design ◽  
Dwelling Time ◽  
Design And Optimization ◽  
Different Temperatures ◽  
The Given

ZnO-based varistor; Microstructure; design and optimization; Electrical properties Abstract. ZnO-based ceramic varistors of a commercially available ZnO-based varistor composition were prepared under sintering system of different temperatures and dwelling times. The microstructure and electrical properties were investigated systematically and optimized. With increasing sintering temperature from 1035 to 1175 °C and dwelling time from 1 to 4 h, the composition and microstructure phases of the samples almost had no change, but the samples prepared at 1035 and 1175 °C presented the highest porosity; the nonlinear coefficient generally increased, but the samples prepared at 1145 and 1175 °C almost presented the same value of nonlinear coefficient; the varistor voltage decreased; and the samples sintered at 1035 and 1175 °C presented the highest leakage current. From the microstructure and electrical performance, it was proposed that, for the given varistors, the optimum sintering system was 1145 °C for 2 h.

Effect of Sintering Temperature on the Microstructure and Electrical Properties of SnO2-Based Varistors

2012 ◽  
Vol 724 ◽  
pp. 323-326
Author(s):  
Guang Liang Hu ◽  
Jian Feng Zhu
Keyword(s):  
Grain Size ◽  
Electrical Properties ◽  
Leakage Current ◽  
Sintering Temperature ◽  
Nonlinear Coefficient

SnO2-based varistors were successfully fabricated from the mixed powders, SnO2, Co2O3, Nb2O5 and Cr2O3. The effects of sintering temperature (1250, 1300, 1350 and 1400 °C) on the microstructure and electrical properties were investigated. The results reveal that the grain size increases with increasing the sintering temperature, and the breakdown electrical filed decreases gradually. When the sintering temperature was 1300 °C, the nonlinear coefficient of the as fabricated SnO2 based varistors presents the maximum of 27. Meanwhile, the leakage current possesses the minimum of 4.5 µA.

Synthesis of Pr6O11 Doped ZnO-Based Varistors by Pyrogenic Decomposition of Nitrate

2011 ◽  
Vol 675-677 ◽  
pp. 179-182
Author(s):  
Jian Feng Zhu ◽  
Guo Quan Qi ◽  
Hai Bo Mao ◽  
Hai Bo Yang ◽  
Fen Wang
Keyword(s):  
Grain Size ◽  
Electrical Properties ◽  
Leakage Current ◽  
Sintering Temperature ◽  
Linear Coefficient ◽  
Average Grain Size ◽  
Non Linear ◽  
Different Temperatures ◽  
Zno Powders ◽  
Doped Zno

Pr6O11 doped ZnO-based varistor powders were prepared by a method of pyrogenic decomposition nitrate, which were together with ZnO powders, made into rounded mass and sintered at different temperatures. The effects of sintering temperatures on the composition, microstructure and electrical properties of Pr6O11 doped ZnO-based varistors were investigated. The results show that the optimum sintering temperature is at 1150 °C with 6 μm ZnO average grain size and the samples possess the advantageous electrical properties: varistor voltage of about 480 V/mm, non linear coefficient reaching 44 and leakage current of 0.7 μA.

scholarly journals Synergistic Effects of Pr6O11 and Co3O4 on Electrical and Microstructure Features of ZnO-BaTiO3 Varistor Ceramics

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 702
Author(s):  
Muhamad Syaizwadi Shaifudin ◽  
Mohd Sabri Mohd Ghazali ◽  
Wan Mohamad Ikhmal Wan Mohamad Kamaruzzaman ◽  
Wan Rafizah Wan Abdullah ◽  
Syara Kassim ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Leakage Current ◽  
Breakdown Voltage ◽  
Synergistic Effects ◽  
Nonlinear Coefficient ◽  
Ceramic Materials ◽  
Electrical Performance

This paper investigated the effects of Pr6O11 and Co3O4 on the electrical properties of ZnO-BaTiO3 varistor ceramics. The Pr6O11 doping has a notable influence on the characteristics of the nonlinear coefficient, varistor voltage, and leakage current where the values varied from 2.29 to 2.69, 12.36 to 68.36 V/mm and 599.33 to 548.16 µA/cm2, respectively. The nonlinear varistor coefficient of 5.50 to 7.15 and the varistor voltage of 7.38 to 8.10 V/mm was also influenced by the use of Co3O4 as a dopant. When the amount of Co3O4 was above 0.5 wt.%, the leakage current increased from 202.41 to 302.71 μA/cm2. The varistor ceramics with 1.5 wt.% Pr6O11 shows good nonlinear electrical performance at higher breakdown voltage and reduced the leakage current of the ceramic materials. Besides, the varistor sample that was doped with 0.5 wt.% Co3O4 was able to enhance the nonlinear electrical properties at low breakdown voltage with a smaller value of leakage current.

Performance of (Y2O3,V2O5) Co-Doping TiO2 Ceramics

2016 ◽  
Vol 697 ◽  
pp. 271-274
Author(s):  
Gui Min Jiang ◽  
Ji Kang Yan ◽  
Gang Yang ◽  
Zhi Cao Duan ◽  
Kun Yong Kang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Sintering Temperature ◽  
Nonlinear Coefficient ◽  
Electrical Performance ◽  
Varistor Ceramic ◽  
Co Doping

The present study investigated the effect of the sintering temperature and (Y2O3, V2O5) co-doping on the performance of TiO2 varistor ceramic which has lower varistor voltage and high nonlinear coefficient. The results showed that the TiO2-based varistor ceramic which doped with 0.35% mol and 0.25% mol of Y2O3 and V2O5 has good comprehensive electrical performance and excellent dielectric constant sintered at 1200°C. Its varistor voltage V1mA is 38.1V, nonlinear coefficient is 4.6.

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.

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.

Effect of Temperature on Microstructure and Electrical Properties of (Y, Ta)-Doped TiO2 Capacitor-Varistor Ceramics

2011 ◽  
Vol 214 ◽  
pp. 173-177
Author(s):  
Tian Guo Wang ◽  
Qun Qin ◽  
Wen Jun Zhang
Keyword(s):  
Dielectric Properties ◽  
Electrical Properties ◽  
Breakdown Voltage ◽  
Sintering Temperature ◽  
Nonlinear Coefficient ◽  
Effect Of Temperature ◽  
Electrical Characteristics ◽  
Electrical Behavior ◽  
Nonlinear Properties ◽  
Electrical Permittivity

The microstructure and nonlinear electrical behavior and dielectric properties of the varistor, which are composed of (Y2O3, Ta2O5)-doped TiO2 ceramics, were investigated for various sintering temperatures. It is assumed that the moderate sintering temperature improves the permitivity of TiO2 ceramics, together with high nonlinear properties. The varistor of 99.6 mol%-0.3 mol%Y2O3-0.1 nol%Ta2O5 composite sintered at 1400 °C has a maximal nonlinear coefficient of α =4.4, a low breakdown voltage of 10.8 V/mm, the ultrahigh electrical permittivity of 7.73× 104 and low tanδ of 0.34. The sintering temperature plays an important an important role on the nonlinear electrical characteristics and dielectric properties of the ceramics through its influences on the microstructure of samples.

Study on Microstructure of ZnO Lighting Arrester with High Voltage Gradient

2011 ◽  
Vol 415-417 ◽  
pp. 1070-1073
Author(s):  
Mo He ◽  
Qi Bin Liu ◽  
Chang Qi Xia
Keyword(s):  
Electrical Properties ◽  
Leakage Current ◽  
High Voltage ◽  
Sintering Temperature ◽  
Holding Time ◽  
Experimental Results ◽  
Voltage Gradient ◽  
Volume Method ◽  
Mass Volume

To obtain ZnO arrester with high voltage gradient and small size, through the optimizing foundamental formula of arrester and changing sintering temperature and holding time, the electrical properties and microstructure of varistors were studied. The density of varistors was determined by using the mass - volume method , voltage gradient and leakage current of ZnO arrester were measured with Ⅱ Surge Arrester Tester DC parameters, microstructure of varistor ceramics were studied by means XRD and SEM. The experimental results show that with increasement of the sintering temperature, the density of varistors increases, and the voltage gradient continues to decrease and leakage current almost keeps unchangable. As the holding time increases, while as the voltage gradient continues to decrease, and leakage current almost unchanges.

Effect of Sintering Temperature on Properties of Multiferroic BaFe12O19/MgFe2O4/BaTiO3 Composites

2016 ◽  
Vol 846 ◽  
pp. 410-415
Author(s):  
M.F.A. Zolkepli ◽  
Rozidawati Awang ◽  
Zalita Zainuddin
Keyword(s):  
Grain Size ◽  
Solid State ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Solid State Reaction Technique ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Tetragonal Batio

In this paper, the structural, magnetic and electrical properties of multiferroic BaFe12O19/MgFe2O4/BaTiO3 composites have been studied. BaFe12O19/MgFe2O4/BaTiO3 composites were synthesized by using the conventional solid state reaction technique and sintered at different temperatures. XRD analysis confirmed the existence of hexagonal BaFe12O19, cubic spinel MgFe2O4 and tetragonal BaTiO3 for ferrites and ferroelectric phases, respectively. The suitable sintering temperature for preparing BaFe12O19/MgFe2O4/BaTiO3 composites is between 1000 °C and 1050 °C. SEM analysis showed that as a whole the grain size increases and the pores is reduced with sintering temperature; thus the sample became denser. The coercive field and saturation magnetization decreases when sintering temperature is increased. Resistance of the samples decrease from 103 kW to 19 kW while the capacitance increases from 0.8 nF to 4.0 nF with sintering temperature.

Electrical Properties of Hot Press Sintered NASICON Ceramics

2007 ◽  
Vol 334-335 ◽  
pp. 149-152 ◽  
Author(s):  
Dong Mei Zhu ◽  
Zhang Long Xie ◽  
Fa Luo ◽  
Wan Cheng Zhou
Keyword(s):  
Ionic Conductivity ◽  
Electrical Properties ◽  
Crystal Size ◽  
Sintering Temperature ◽  
Dielectric Constants ◽  
Hot Press ◽  
Frequency Increase ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Hot Press Process

Sodium superionic conductor, NASICON ceramic (Na1+xZr2SixP3-xO12, x=2), was hot-press sintered under different temperatures and the electrical properties of the obtained different samples were investigated. Results show that the relative density of the ceramics can be improved by hot-press process efficiently and the crystal size of the samples are closely related to sintering temperature. With the increase of sintering temperature, both the density and the crystal size of samples increase obviously, resulting in the increase of ionic conductivity of samples as the sintering temperature. When the sintering temperature reaches 1150oC, the ionic conductivity of sample is as high is 3.6×10-3S/cm, which is obviously higher than that of sample sintered at 1000oC (2.13×10-3S/cm). As the frequency increase, the real parts and the imaginary parts of complex dielectric constants for all the samples decrease in 8.2 GHz~12.4GHz frequency band. The ceramics obtained at the higher temperature possess the higher dielectric constant.

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