HIGH POTENTIAL GRADIENT OF ZnO VARISTORS PREPARED BY Y2O3-DOPING AND LOW-TEMPERATURE SINTERING

2009 ◽  
Vol 23 (25) ◽  
pp. 3013-3022 ◽  
Author(s):  
LEI KE ◽  
DONG-MEI JIANG ◽  
CHUN-XIA WANG ◽  
XUE-MING MA
Keyword(s):  
Low Temperature ◽  
Sintering Temperature ◽  
Early Period ◽  
Potential Gradient ◽  
High Energy ◽  
High Potential ◽  
Low Temperature Sintering ◽  
Experimental Conditions ◽  
Zno Varistors ◽  
Lower Temperature

A high potential gradient of ZnO varistors were fabricated by Y 2 O 3-doping and low-temperature sintering. The value of the potential gradient increased to 2460.5 V/mm with the Y 2 O 3 content of 0.08 mol% and the sintering temperature of 800°C. The effects of Y 2 O 3-doping and sintering temperature on the electrical properties of ZnO varistors were investigated. Under the given experimental conditions, additive Y 2 O 3 exists in the form of Y 2 O 3 phase after sintering at 800°C. High-energy ball-milling in the early period of the experiment induced the grain refinement and realized the sintering formation at the lower temperature of 800°C. Both Y 2 O 3-doping and low-temperature sintering restrained the ZnO grain growth and increased the potential gradient.

scholarly journals Preparation of Ultrahigh Potential Gradient of ZnO Varistors by Rare-Earth Doping and Low-Temperature Sintering

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Lei Ke ◽  
Ming Hu ◽  
Xueming Ma
Keyword(s):  
Grain Size ◽  
Rare Earth ◽  
Low Temperature ◽  
Potential Gradient ◽  
Schottky Barriers ◽  
Rare Earth Doping ◽  
Low Temperature Sintering ◽  
Experimental Conditions ◽  
Zno Varistors ◽  
The Given

The effects of rare-earth doping and low-temperature sintering on electrical properties of ZnO varistors were investigated. The potential gradient (E1mA) of the ZnO varistors increased significantly to 2247.2 V/mm after doping 0.08 mol% of Y2O3 and sintering at 800°C for 2 h. The notable decrease of the grain size with the given experimental conditions was the origin for the increase in E1mA. During the process of high-temperature sintering, both the oxygen at the grain boundary interface and the neutralisation of the ions on the depletion layer were directly reduced, which caused the weight loss and the internal derangement of double Schottky barriers.

Low-temperature sintering of high potential gradient B2O3-doped ZnO varistors

2015 ◽  
Vol 26 (7) ◽  
pp. 4997-5000 ◽  
Author(s):  
Zhijun Xu ◽  
Shuai Ma ◽  
Ruiqing Chu ◽  
Jigong Hao ◽  
Lihong Cheng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Potential Gradient ◽  
High Potential ◽  
Low Temperature Sintering ◽  
Zno Varistors ◽  
Doped Zno

scholarly journals In Search of Magnetic Properties of Samarium Cobalt (Sm2Co17) within a Low-Temperature Sintering Process

2021 ◽  
Vol 16 (3) ◽  
pp. 517-524
Author(s):  
Poppy Puspitasari ◽  
A. Muhammad ◽  
A. A. Permanasari ◽  
T. Pasang ◽  
S. M. S. N. S. Zahari ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Magnetic Properties ◽  
Low Temperature ◽  
Functional Groups ◽  
Sintering Temperature ◽  
Alkyl Halides ◽  
High Coercivity ◽  
Low Temperature Sintering ◽  
Magnetic Anisotropy Energy ◽  
Low Sintering Temperature

Samarium cobalt is known as super high density magnetic material with large magnetic anisotropy energy. Samarium–cobalt exhibits manipulative magnetic properties as a rare-earth material which has different properties in a low sintering temperature. It is therefore of paramount importance to investigate samarium cobalt (Sm2Co17) magnetic properties in the low temperature sintering condition. Sm2Co17, which is utilized in this research, is synthesized via the sol–gel process at sintering temperatures of 400, 500, and 600 °C. Subsequently, the crystallites indicate the formation of a single-phase Sm2Co17 on all the samples in all temperature variations. Moreover, the peaks in the X-ray diffraction analysis of crystallite sizes calculated using the Scherrer equation are 17.730, 15.197, and 13.296 nm at 400, 500, and 600 °C. Through scanning electron microscopy, the particles are found to be relatively large and agglomerated, with average sizes of 143.65, 168.78, and 237.26 nm. The functional groups are also analyzed via Fourier-transform infrared spectroscopy, which results in the appearance of several bonds in the samples, for example, alkyl halides, alkanes, and esters with aromatic functional groups on the fingerprint area and alkynes, alkyl halides, and alcohol functional groups at a wavelength of above 1500 cm. The test results of the magnetic properties using vibrating-sample magnetometer (VSM) revealed high coercivity and retentivity in the samples sintered at 400 °C. However, the highest saturation occurs in the samples sintered at 600 ℃. At a low sintering temperature (below 1000 °C), samarium cobalt shows as the soft magnetic material. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Low temperature sintering of nano-SiC using a novel Al8B4C7 additive

2010 ◽  
Vol 25 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Sea-Hoon Lee ◽  
Byung-Nam Kim ◽  
Hidehiko Tanaka
Keyword(s):  
Grain Size ◽  
Liquid Phase ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Applied Pressure ◽  
Liquid Phase Sintering ◽  
Low Temperature Sintering ◽  
Densification Rate ◽  
Sintering Additive ◽  
Average Grain Size

Al8B4C7 was used as a sintering additive for the densification of nano-SiC powder. The average grain size was approximately 70 nm after sintering SiC-12.5wt% Al8B4C7 at 1550 °C. The densification rate strongly depended on the sintering temperature and the applied pressure. The rearrangement of SiC particles occurred at the initial shrinkage, while viscous flow and liquid phase sintering became important at the middle and final stage of densification.

Studies on Structural, Microwave Dielectric Properties, and Low-Temperature Sintering of 1.52Li2O-0.36Nb2O5-1.34TiO2 Ceramic

2012 ◽  
Vol 512-515 ◽  
pp. 1226-1230
Author(s):  
Qun Zeng ◽  
Yong Heng Zhou
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramic ◽  
Low Temperature Sintering ◽  
Dielectric Ceramic ◽  
Microwave Dielectric ◽  
M Phase ◽  
Two Phases

The structure, microwave dielectric properties and low-temperature sintering of a new Li2O-Nb2O5-TiO2 system ceramic with the Li2O: Nb2O5: TiO2 mole ratio of 1.52: 0.36: 1.34 have been investigated in this study. The 1.52Li2O-0.36Nb2O5-1.34TiO2 (LNT) ceramic is composed of two phases, the “M-Phase” and Li2TiO3 solid solution (Li2TiO3ss) phase. This new microwave dielectric ceramic has low intrinsic sintering temperature ( ~ 1100 oC ) and good microwave dielectric properties of middle permittivity (εr ~38.6), high Q×f value up to 7712 GHz, and near zero τf value (~ 4.64 ppm/oC). In addition, the sintering temperature of the LNT ceramics could be lowered down effectively from 1100 oC to 900 oC by adding 1 wt.% B2O3. Good microwave dielectric properties of εr = 42.5, Q*f =6819 GHz and τf = 2.7 ppm/oC could be obtained at 900 oC, which indicate the ceramics would be promising candidates for low-temperature co-fired ceramics (LTCC) applications.

High energy density hybrid Mg2+/Li+ battery with superior ultra-low temperature performance

2016 ◽  
Vol 4 (6) ◽  
pp. 2277-2285 ◽  
Author(s):  
Zhonghua Zhang ◽  
Huimin Xu ◽  
Zili Cui ◽  
Pu Hu ◽  
Jingchao Chai ◽  
...  
Keyword(s):  
Energy Density ◽  
Low Temperature ◽  
High Energy ◽  
High Potential ◽  
High Energy Density ◽  
Polar Regions ◽  
Capacity Retention ◽  
Temperature Performance ◽  
Li Battery ◽  
Low Temperature Performance

A hybrid Mg2+/Li+ battery operates at a high potential of 2.45 V and delivers superior properties, especially at ultra-low temperature (77% capacity retention at −40 °C), which is preferable for many peculiar fields and places, such as polar regions, aerospace, and deep offshore waters.

Low Temperature Sintering of (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 Microwave Dielectric Ceramics

2010 ◽  
Vol 663-665 ◽  
pp. 1028-1031
Author(s):  
Yue Ming Li ◽  
Hua Zhang ◽  
Zhu Mei Wang ◽  
Yan Hong ◽  
Zong Yang Shen
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Low Temperature Sintering ◽  
Microwave Dielectric Ceramics ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

The sintering behavior and microwave dielectric properties of the (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 (CSLST) ceramics doped with different amounts of Li2O-B2O3-SiO2-CaO-Al2O3 (LBSCA) glass were investigated. The sintering temperature of the CSLST ceramics can be effectively reduced over 200oC due to the addition of LBSCA glass. For the 5 wt% LBSCA-doped CSLST ceramics, which are sintered at only 1000 oC for 5 h, show optimum microwave dielectric properties as follows: εr=84.74, Qf=2446 GHz and τf=-12.48 ppm/oC.

Low Temperature Sintering Ba3Ti5Nb6O28 Ceramics with Tunable Temperature Coefficient of Dielectric Constant

2008 ◽  
Vol 368-372 ◽  
pp. 170-172 ◽  
Author(s):  
Dong Guo ◽  
Zhi Yuan Ling ◽  
Xing Hu
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Low Temperature ◽  
Temperature Coefficient ◽  
Sintering Temperature ◽  
Low Temperature Sintering

A middle permittivity dielectrics with the tunable temperature coefficient of dielectric constant (τε) in the BaO-TiO2-Nb2O5 system, Ba3Ti5Nb6O28, has been synthesized and characterized. The dielectric properties of Ba3Ti5Nb6O28 measured at 1MHz are as follows: dielectric constant (εr) ~38, dielectric loss (tanδ)<0.0002, temperature coefficient of dielectric constant (τε)~-22ppm/°C. The Ba3Ti5Nb6O28 phase satisfies the requirements of NP0 (MLCC) dielectrics, but the sintering temperature of the Ba3Ti5Nb6O28 phase (1250~1300°C) is too high to be co-fired with Ag or Cu electrodes. To lower the sintering temperature, an appropriate amount of ZnO-B2O3 frit (5~7wt.%) was added to the Ba3Ti5Nb6O28 phase and dense ceramics were obtained at the sintering temperature lower than 1000°C. Furthermore, the CaNb2O6 phase with the positive τε of 65ppm/°C was incorporated into the Ba3Ti5Nb6O28 phase to adjust the temperature coefficient of dielectric constant from negative to positive(-22~30ppm/°C). Near zero τε ceramics with high εr (38) and low tanδ (0.0002) were obtained at the composition of Ba3Ti5Nb6O28/ CaNb2O6/ ZB frit=76:17:7 wt.%.

Low Temperature Sintering of Lead-Free BaTiO3-Based X9R Ceramics with Bi2O3 Dopant and Assisted by LiF-CaF2 Flux Agent

2014 ◽  
Vol 906 ◽  
pp. 31-36 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jun Zhang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Temperature Stability ◽  
Lead Free ◽  
Low Temperature Sintering ◽  
Pure Silver ◽  
Flux Agent ◽  
Low Sintering Temperature

The sintering temperature of BaTiO3powder was reduced to 950°C due to the Bi2O3-LiF-CaF2addition.Excellent densification was achieved after sintering at 950°C for 10h. The low sintering temperature of newly developed capacitor materials allows a co-firing with pure silver electrodes.The dielectric constant and the temperature stability of the dielectric constant satisfied the X9R standard, which dielectric properties of were ε25°C1115, ΔC/C25°C±12% (55~200°C), tanδ1.5% (25°C).

Sign in / Sign up

Export Citation Format

Share Document