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http://dx.doi.org/10.3740/MRSK.2012.22.12.675

Sintering and Electrical Properties According to Sb/Bi Ratio(I) : ZnO-Bi2O3-Sb2O3-Mn3O4-Cr2O3 Varistor  

Hong, Youn-Woo (Electronic Materials Convergence Division, KICET)
Lee, Young-Jin (Electronic Materials Convergence Division, KICET)
Kim, Sei-Ki (Electronic Materials Convergence Division, KICET)
Kim, Jin-Ho (School of Materials Science and Engineering, Kyungpook National University)
Publication Information
Korean Journal of Materials Research / v.22, no.12, 2012 , pp. 675-681 More about this Journal
Abstract
We aimed to examine the co-doping effects of 1/6 mol% $Mn_3O_4$ and 1/4 mol% $Cr_2O_3$ (Mn:Cr = 1:1) on the reaction, microstructure, and electrical properties, such as the bulk defects and grain boundary properties, of ZnO-$Bi_2O_3-Sb_2O_3$ (ZBS; Sb/Bi = 0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Mn,Cr-doped ZBS, ZBS(MnCr) varistors were controlled using the Sb/Bi ratio. Pyrochlore ($Zn_2Bi_3Sb_3O_{14}$), ${\alpha}$-spinel ($Zn_7Sb_2O_{12}$), and ${\delta}-Bi_2O_3$ (also ${\beta}-Bi_2O_3$ at Sb/Bi ${\leq}$ 1.0) were detected for all of the systems. Mn and Cr are involved in the development of each phase. Pyrochlore was decomposed and promoted densification at lower temperature on heating in Sb/Bi = 1.0 system by Mn rather than Cr doping. A more homogeneous microstructure was obtained in all systems affected by ${\alpha}$-spinel. In ZBS(MnCr), the varistor characteristics were improved dramatically (non-linear coefficient, ${\alpha}$ = 40~78), and seemed to form ${V_o}^{\cdot}$(0.33 eV) as a dominant defect. From impedance and modulus spectroscopy, the grain boundaries can be seen to have divided into two types, i.e. one is tentatively assigned to ZnO/$Bi_2O_3$ (Mn,Cr)/ZnO (0.64~1.1 eV) and the other is assigned to the ZnO/ZnO (1.0~1.3 eV) homojunction.
Keywords
ZnO varistor; electrical properties; $Mn_3O_4$; $Cr_2O_3$; sintering;
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1 F. Greuter and G. Blatter, Semicond. Sci. Technol., 5, 111 (1990).   DOI   ScienceOn
2 M. Inada and K. Matsuoka, Advances in Ceramics; Vol. 7, p.91, edited by M. F. Yan and A. H. Heuer, American Ceramic Society, Columbus, OH, USA (1984).
3 J. Kim, T. Kimura and T. Yamaguchi, J. Am. Ceram. Soc., 72, 1390 (1989).   DOI   ScienceOn
4 Y. W. Hong and J. H. Kim, J. Kor. Ceram. Soc., 37, 651 (2000) (in Korean).
5 Y. -W. Hong, H. -S. Shin, D. -H. Yeo, J. -H. Kim and J. -H. Kim, J. KIEEME, 21, 738 (2008) (in Korean).
6 L. Karanovic , D. Poleti and D. Vasovi , Mater. Lett., 18, 191 (1994).   DOI   ScienceOn
7 A. Mergen and W. E. Lee, J. Eur. Ceram. Soc., 17, 1049 (1997).   DOI   ScienceOn
8 Z. Brankovic, G. Brankovic, D. Poleti and J. A. Varela, Ceram. Int., 27, 115 (2001).   DOI   ScienceOn
9 Y. -W. Hong, H. -S. Shin, D. -H. Yeo and J. -H. Kim, J. KIEEME, 23, 942 (2010) (in Korean).
10 A. R. West and M. Andres-Verges, J. Electroceram., 1, 125 (1997).   DOI
11 K. A. Abdullah, A. Bui and A. Loubiere, J. Appl. Phys., 69, 4046 (1991).   DOI
12 I. M. Hodge, M. D. Ingram and A. R. West, J. Electroanal. Chem., 74, 125 (1976).   DOI   ScienceOn
13 R. Gerhardt, J. Phys. Chem. Solids, 55, 1491 (1994).   DOI   ScienceOn
14 Y. -W. Hong, H. -S. Shin, D. -H. Yeo, J. -H. Kim and J. -H. Kim, J. KIEEME, 22, 941 (2009) (in Korean).
15 Y. -W. Hong, H. -S. Shin, D. -H. Yeo and J.-H. Kim, J. KIEEME, 24, 969 (2011) (in Korean).
16 Y. W. Hong and J. H. Kim, Ceram. Int., 30, 1307 (2004).   DOI   ScienceOn
17 B. S. Chiou and M. C. Chung, J. Electron. Mater., 20, 885 (1991).   DOI
18 P. R. Bueno, J. A. Varela and E. Longo, J. Eur. Ceram. Soc., 28, 505 (2008).   DOI   ScienceOn
19 K. Eda, IEEE Electr. Insul. Mag., 5(6), 28 (1989).
20 D. R. Clarke, J. Am. Ceram. Soc., 82, 485 (1999).
21 R. Einzinger, Annu. Rev. Mater. Sci., 17, 299 (1987).   DOI