ZnO Varistors for Transient Protection

1977 ◽  
Vol 13 (4) ◽  
pp. 338-343 ◽  
Author(s):  
L. Levinson ◽  
H. Philipp
Keyword(s):  
Zno Varistors

Microchemistry of ZnO Varistors

1992 ◽  
Vol 50 (2) ◽  
pp. 1694-1695
Author(s):  
K. K. Soni ◽  
J. Hwang ◽  
V. P. Dravid ◽  
T. O. Mason ◽  
R. Levi-Setti
Keyword(s):  
Grain Boundaries ◽  
Multiple Roles ◽  
Grain Boundary Engineering ◽  
Ion Microprobe ◽  
Dopant Distribution ◽  
Important Ingredient ◽  
Zno Varistor ◽  
Zno Varistors ◽  
Zno Powder ◽  
The University

ZnO varistors are made by mixing semiconducting ZnO powder with powders of other metal oxides e.g. Bi2O3, Sb2O3, CoO, MnO2, NiO, Cr2O3, SiO2 etc., followed by conventional pressing and sintering. The non-linear I-V characteristics of ZnO varistors result from the unique properties that the grain boundaries acquire as a result of dopant distribution. Each dopant plays important and sometimes multiple roles in improving the properties. However, the chemical nature of interfaces in this material is formidable mainly because often trace amounts of dopants are involved. A knowledge of the interface microchemistry is an essential component in the ‘grain boundary engineering’ of materials. The most important ingredient in this varistor is Bi2O3 which envelopes the ZnO grains and imparts high resistance to the grain boundaries. The solubility of Bi in ZnO is very small but has not been experimentally determined as a function of temperature.In this study, the dopant distribution in a commercial ZnO varistor was characterized by a scanning ion microprobe (SIM) developed at The University of Chicago (UC) which offers adequate sensitivity and spatial resolution.

Effects of Sb, Zr, or Y addition on Electrical Degradation Characteristics of ZnO Varistors

2011 ◽  
Vol 131 (3) ◽  
pp. 219-224
Author(s):  
Takayuki Watanabe ◽  
Ai Fukumori ◽  
Yuji Akiyama ◽  
Masayuki Takada ◽  
Yuuki Sato ◽  
...  
Keyword(s):  
Electrical Degradation ◽  
Zno Varistors

Effects of Zr and Y Addition on the Electrical Degradation Characteristics of ZnO Varistors

2010 ◽  
Vol 130 (4) ◽  
pp. 394-402 ◽  
Author(s):  
Yuji Akiyama ◽  
Masayuki Takada ◽  
Ai Fukumori ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Electrical Degradation ◽  
Zno Varistors

Synthesis and characterization of multilayered ZnO/glass/ZnO varistors

2020 ◽  
Author(s):  
C. P. E. Varsamis ◽  
C. Valvi ◽  
N. Makris ◽  
E. I. Kamitsos
Keyword(s):  
Synthesis And Characterization ◽  
Zno Varistors

Effectively enhanced comprehensive electrical performance of ZnO varistors by a fast combinatorial refinement method

2021 ◽  
Vol 133 ◽  
pp. 105945
Author(s):  
Zhuyun Li ◽  
Xin Ren ◽  
Xin Wang ◽  
Wanli You ◽  
Meilian Zhong ◽  
...  
Keyword(s):  
Electrical Performance ◽  
Refinement Method ◽  
Zno Varistors

The Effect of Point Defects on DC Degradation of ZnO Varistors

2020 ◽  
Author(s):  
Xia Zhao ◽  
Weidong Shi ◽  
Boyu Zhang ◽  
Men Guo ◽  
Yao Wang ◽  
...  
Keyword(s):  
Point Defects ◽  
Zno Varistors

Microstructures and characteristics of deep trap levels in ZnO varistors doped with Y2O3

2009 ◽  
Vol 52 (12) ◽  
pp. 3668-3673 ◽  
Author(s):  
Jun Liu ◽  
Jun Hu ◽  
JinLiang He ◽  
YuanHua Lin ◽  
WangCheng Long
Keyword(s):  
Deep Trap ◽  
Zno Varistors ◽  
Deep Trap Levels ◽  
Trap Levels

A barrier model for ZnO varistors

1979 ◽  
Vol 50 (7) ◽  
pp. 4847-4855 ◽  
Author(s):  
P. L. Hower ◽  
T. K. Gupta
Keyword(s):  
Zno Varistors ◽  
Barrier Model

The Effect of Transition of Valence State of Additives on Electrical Degradation of ZnO Varistors

2002 ◽  
Vol 228-229 ◽  
pp. 233-236
Author(s):  
Yohei Satoi ◽  
Takanori Ishikawa ◽  
Takahiro Kaneyoshi ◽  
Shinzo Yoshikado
Keyword(s):  
Valence State ◽  
Electrical Degradation ◽  
Zno Varistors
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