A barrier model for ZnO varistors

1979 ◽  
Vol 50 (7) ◽  
pp. 4847-4855 ◽  
Author(s):  
P. L. Hower ◽  
T. K. Gupta
Keyword(s):  
2013 ◽  
Vol 582 ◽  
pp. 181-184 ◽  
Author(s):  
Eiichi Koga ◽  
Masayuki Hogiri ◽  
Yoshiko Higashi

The grain-boundary and its electrical characteristics in SrCoO3doped ZnO varistors were studied. The grain-boundary around ZnO-grain is probably composed of SrCoO3, and its electrical behavior is clearly different from two conventional types of Bi-and Pr-based ZnO varitors. The non-linearity and characteristic behavior could be explained by considering the n-p-n hetero-structure at the grain boundary. SrCoO3 in the grain-boundary region should play crucial roles of not only the appearance of non-liner property but also the formation of different hetero-structure from double Schottky-barrier model on conventional varistors.


Author(s):  
K. K. Soni ◽  
J. Hwang ◽  
V. P. Dravid ◽  
T. O. Mason ◽  
R. Levi-Setti

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.


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

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

2020 ◽  
Author(s):  
C. P. E. Varsamis ◽  
C. Valvi ◽  
N. Makris ◽  
E. I. Kamitsos

2021 ◽  
Vol 133 ◽  
pp. 105945
Author(s):  
Zhuyun Li ◽  
Xin Ren ◽  
Xin Wang ◽  
Wanli You ◽  
Meilian Zhong ◽  
...  

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