Effect of Calcination of the Raw Materials on the Microstructure and Electrical Properties of ZnO-Based Linear Resistance Ceramics

2012 ◽  
Vol 724 ◽  
pp. 327-330
Author(s):  
Jian Feng Zhu ◽  
Yong Zhou
Keyword(s):  
Electrical Properties ◽  
Temperature Coefficient ◽  
Raw Materials ◽  
Nonlinear Coefficient ◽  
Ceramic Method ◽  
Linear Resistance ◽  
Resistance Temperature Coefficient

ZnO-based linear resistance ceramics were fabricated by the conventional ceramic method. The effect of calcination of the raw materials on the microstructure and electrical properties was investigated in detail. The results show that the electrical properties, such as resistivity, nonlinear coefficient and resistance temperature coefficient, have been obviously influenced by the calcining process. The optimal samples fabricated with the materials calcinated for twice possess the highest stabilization of resistivity. Meanwhile, the resistance temperature coefficient is improved by 30%, and the nonlinear coefficient of voltage decreases to 1.16, decreased by 20.7%.

Influence of Al2O3 Doping on the Microstructure and Current–Voltage Characteristics of ZnO-Based Linear Resistance Ceramics

2011 ◽  
Vol 480-481 ◽  
pp. 556-559
Author(s):  
Jian Feng Zhu ◽  
Yong Zhou ◽  
Hai Bo Yang ◽  
Fen Wang
Keyword(s):  
Electrical Properties ◽  
Temperature Coefficient ◽  
Raw Materials ◽  
Nonlinear Coefficient ◽  
Al2o3 Content ◽  
Linear Resistance ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Resistance Temperature Coefficient ◽  
Al2o3 Doping

ZnO-based linear resistance ceramics were synthesized using Al2O3 doped ZnO-based system as raw materials by sintered at 1340 °C for 3 h. The effects of Al2O3 content ranged from 1 to 15 wt% on the microstructure and electrical properties of the ceramics were investigated in detail. The results show that the electrical properties such as nonlinear coefficient, resistivity and resistance temperature coefficient have been obviously influenced by Al2O3 doping. The optimal samples obtained by doping Al2O3 with 9 wt% have a nonlinear coefficient of 1.3, resistivity of 130 (Ω•cm) and resistance temperature coefficient of -5.4×10-3/ °C.

Microstructure and Electrical Properties of CeO2-Doped WO3 Ceramics Prepared by Nanopowders

2007 ◽  
Vol 280-283 ◽  
pp. 381-384
Author(s):  
Xin Sheng Yang ◽  
Yu Wang ◽  
Liang Dong
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
High Dielectric Constant ◽  
Raw Materials ◽  
Nonlinear Coefficient ◽  
Metallic Behavior ◽  
High Dielectric ◽  
Increasing Temperature ◽  
Semiconducting Behavior

CeO2-doped WO3 ceramics were fabricated by using nanometer WO3 and CeO2 powders as raw materials. The microstructure and electrical properties were studied. The ceramics have relatively low breakdown voltage and high dielectric constant. The nonlinear coefficient does not decrease with the increase of the ambient temperature. The electrical conductivity decreases with increasing temperature, indicating that the ceramics have metallic behavior instead of semiconducting behavior.

Effect of Ball Milling of Composite Additives on the Microstructure and Electrical Properties of ZnO Varistors

2011 ◽  
Vol 695 ◽  
pp. 581-584
Author(s):  
Jian Feng Zhu ◽  
Guo Quan Qi ◽  
Hai Bo Yang ◽  
Fen Wang
Keyword(s):  
Electrical Properties ◽  
Ball Milling ◽  
Phase Distribution ◽  
Raw Materials ◽  
Nonlinear Coefficient ◽  
Boundary Phase ◽  
Zno Varistor ◽  
Zno Powders ◽  
Second Phases ◽  
Zno Varistors

ZnO varistors were synthesized with ZnO powders and intensity milled composite additives as raw materials. The effect of milling time of the composite additives on the grain boundary phase distribution as well as the electrical properties was investigated in detail. The results show that ball milling composite additives have a significant effect on the ZnO varistors. The samples derived from ball milled composite additives possess the smaller size and more uniform distribution of the second phases, which improved the electrical properties obviously. The optimal ZnO varistor samples were obtained by ball milling 15 h for the composite additives, which possess average ZnO crystalline grain size of about 4 µm, the gradient voltage V1mA of 454 V/mm, the leakage current IL of 0.12 µA, and the nonlinear coefficient α of 55.

scholarly journals Effects of Ta2O5 on the microstructure and electrical properties of ZnO linear resistance ceramics

2022 ◽  
Author(s):  
Meizhen Zhuo ◽  
Chun-e Huang ◽  
Changzhi Zhao ◽  
Jiongjiong Yin ◽  
Chunying Shen
Keyword(s):  
Electrical Properties ◽  
Grain Boundary ◽  
Electric Fields ◽  
Crystalline Phase ◽  
Nonlinear Coefficient ◽  
Linear Resistance ◽  
Main Crystalline Phase ◽  
Method Effects ◽  
The Stability ◽  
Grain Boundary Barrier

Abstract ZnO-Al2O3-MgO-TiO2-SiO2-Ta2O5 (ZnO-based) linear resistance ceramics with doping different molar percentages of Ta2O5 were prepared by a conventional ceramics method. Effects of Ta2O5 additives on the phase composition, microstructures, and electrical properties of ZnO-based linear resistive ceramics were investigated. The results show that doping Ta2O5 can refine the grains of the main crystalline phase ZnO and the secondary crystalline phase ZnAl2O4 in terms of microstructure, and also can reduce the grain boundary barrier and optimize the I-V characteristics in terms of electrical properties. In addition, the doping of Ta2O5 can improve the stability of the resistivity , and the impedance frequency indicates that the doping of Ta2O5 makes the sample suitable for high-frequency electric fields. The resistivity of the sample doped with 0.2 mol% Ta2O5 is 56.2 Ω·cm, and this sample has the best grain boundary barrier height, nonlinear coefficient and temperature coefficient of resistance of 0.054 eV, 1.04 and -3.48×10-3 / ℃，respectively.

scholarly journals Structural and Electrical Studies on ZnO-Based Thin Films by Laser Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Shanyue Zhao ◽  
Yinqun Hua ◽  
Ruifang Chen ◽  
Jian Zhang ◽  
Ping Ji
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Electrical Properties ◽  
Grain Boundaries ◽  
Laser Irradiation ◽  
Nonlinear Coefficient ◽  
Acceptor State ◽  
Xrd Pattern ◽  
Electrical Studies ◽  
Structural And Electrical Properties

The effects of laser irradiation on the structural and electrical properties of ZnO-based thin films were investigated. The XRD pattern shows that the thin films were highly textured along thec-axis and perpendicular to the surface of the substrate. Raman spectra reveal that Bi2O3segregates mainly at ZnO-ZnO grain boundaries. After laser irradiation processing, the grain size of the film was reduced significantly, and the intrinsic atomic defects of grain boundaries and Bi element segregated at the grain boundary were interacted frequently and formed the composite defects of acceptor state. The nonlinear coefficient increased to 24.31 and the breakdown voltage reduced to 5.34 V.

Microstructure and Electrical Properties of ZnO-Pr6O11-Dy2O3-Based Varistor Ceramics Doped with La2O3

2007 ◽  
Vol 336-338 ◽  
pp. 680-683
Author(s):  
Jing Nan Cai ◽  
Yuan Hua Lin ◽  
Rong Juan Zhao ◽  
Ce Wen Nan ◽  
Jin Liang He
Keyword(s):  
Rare Earth ◽  
Phase Composition ◽  
Electrical Properties ◽  
Rare Earth Elements ◽  
Leakage Current ◽  
Breakdown Voltage ◽  
Intergranular Phase ◽  
Ceramic Method ◽  
Sem Micrographs ◽  
Ceramic Samples

ZnO-Pr6O11-Dy2O3-based varistor ceramics doped with 0~1.5 mol% La2O3 were fabricated by a conventional ceramic method. All the samples were sintered at 1350 oCfor 2 h. The phase composition and microstructure of the ceramic samples have been investigated by XRD, SEM and EDS. The results of SEM micrographs indicated that the La2O3 additives can promote ZnO grain’s growth, and the rare earth elements dispersed mainly in the intergranular phase observed by EDS. The electrical properties of the samples determined by the V-I curves revealed that the breakdown voltage of samples decreases from 508 V/mm to about 100 V/mm with the increase of La2O3, and the nonlinear exponent also decreases from 20.2 to 13.2. The typical leakage current is about 10.2 μA for the sample doped with 0.5 mol% La2O3.

Microstructure and electrical properties of Sm2O3-doped ZnO-based linear resistance ceramics

2015 ◽  
Vol 27 (1) ◽  
pp. 818-824 ◽  
Author(s):  
Jianfeng Zhu ◽  
Qian Liu ◽  
Jingjing Wang ◽  
Yong Zhou ◽  
Wei Ye ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Linear Resistance ◽  
Doped Zno

SrTiO3 Based Dual-Functional Ceramics with Nano-Additives

2007 ◽  
Vol 336-338 ◽  
pp. 793-795 ◽  
Author(s):  
Hui Ming Ji ◽  
Xiao Chuan Liu ◽  
Ying Lv ◽  
Cui Xia Li ◽  
Xiao Dong Chen
Keyword(s):  
Electrical Properties ◽  
Nonlinear Coefficient ◽  
Liquid Phase Sintering ◽  
Composite Powders ◽  
Voltage Sensing ◽  
Reducing Atmosphere ◽  
Dual Functional ◽  
Donor And Acceptor ◽  
Nano Additives ◽  
Functional Ceramics

The electrical properties and microstructures of SrTiO3 based voltage-sensing and dielectric dual-functional ceramics with nanometer donor and acceptor additives were studied. The La2O3 nanopowders and MnO-SiO2-Al2O3 (or CuO-SiO2-Al2O3) nano-composite powders were incorporated into SrTiO3 as donor, acceptor and liquid-phase sintering aids. Then semiconducting SrTiO3-based ceramics were sintered at 1360-1440oC for 2 h in a reducing atmosphere. The effects of the nanometer donor and acceptor additives and the sintering temperature on the electrical properties and microstructures of materials were discussed. The results showed that SrTiO3-based varistor ceramics with 1.1 mol% La2O3 and 0.1 mol% MnO nano-additives sintered at 1360-1420oC in graphite and N2 reducing atmosphere have excellent voltage-sensing and dielectric characteristics. The varistor voltage ranges from 2.3 to 5.3 V/mm, the nonlinear coefficient from 3.0 to 3.8, and the dielectric constant from 215,600 to 413,000.

Sign in / Sign up

Export Citation Format

Share Document