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Nonlinear property of SrCoO3-doped ZnO ceramics sintered in a reducing atmosphere and multilayer ceramic varistors with base metal electrodes

Published online by Cambridge University Press:  13 August 2015

Yoshiko Higashi ,
Masayuki Hogiri  and
Eiichi Koga
Yoshiko Higashi*
Affiliation:
Corporate Engineering Division, Automotive & Industrial Systems Company, Panasonic Co., Ltd., 1006 Kadoma, Kadoma City, Osaka 571-8506, Japan
Masayuki Hogiri
Affiliation:
Corporate Engineering Division, Automotive & Industrial Systems Company, Panasonic Co., Ltd., 1006 Kadoma, Kadoma City, Osaka 571-8506, Japan
Eiichi Koga
Affiliation:
Circuit Components Business Unit, Automotive & Industrial Systems Company, Panasonic Co., Ltd., 1037-2 Kamiosatsu, Chitose City, Hokkaido 066-8502, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

This study describes the nonlinear characteristics of SrCoO3-doped ZnO varistors and multilayer ceramic varistors (MLCVs) with copper electrodes, both of which are sintered in a reducing atmosphere. Due to postannealing effects in air or N2 with low-oxygen concentration (0.02%), bulk disks can be sintered in a reducing atmosphere, with a usable V1 mA/mm (e.g., 1600 V for bulk bodies or 1200 V for Cu cofiring) and highly nonlinear indices (α10 μA = V1 mA/V10 μA < 1.3), regardless of whether cofiring with Cu electrodes on disk surfaces was conducted or not. On the basis of this procedure, Cu-MLCVs were successfully produced, without oxidation of Cu-internal electrodes or structural defects. They exhibited high stability as well as a useful nonlinearity of V1 mA = 10.4 V and α10 μA = 1.93. The resultant stability against electrostatic discharge (ESD) satisfies the highest standard of level 4 in IEC61000-4-2 (ESD stability test). This is the first report to show that MLCVs with base metals have practical properties, including stability.

Keywords

grain boundariesZnannealing
Type
Articles
Information
Journal of Materials Research , Volume 30 , Issue 15 , 14 August 2015 , pp. 2300 - 2309
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Matsuoka, M.: Nonohmic properties of zinc oxide ceramics. Jpn. J. Appl. Phys. 10, 736 (1971).Google Scholar
Koga, E. and Sawada, N.: Electrical degradation caused by electro-static discharge pulse in ZnO-based multilayer varistor. Key Eng. Mater. 388, 15 (2009).Google Scholar
Koga, E. and Sawada, N.: Multilayer varistor with low-voltage characteristics from ZnO + ACoO3 ceramics (A = Ca, Sr and Ba). Key Eng. Mater. 485, 249–252 (2011).Google Scholar
Koga, E., Sawada, N., Amisawa, M., Minami, S., and Okimoto, T.: Multilayer ceramic chip varistors with low varistor voltage for ESD-protection. Panasonic Tech. J. 58(1), 53–58 (2012).Google Scholar
Stucki, F. and Greuter, F.: Key role of oxygen at zinc oxide varistor grain-boundaries. Appl. Phys. Lett. 57, 446 (1990).Google Scholar
Takeda, T. and Watanabe, H.: Magnetic properties of the system SrCo1-x FexO3-y . J. Phys. Soc. Jpn. 33, 973–978 (1972).Google Scholar
Karzel, H., Potzel, U., Potzel, W., Moser, J., Schäfer, C., Steiner, M., Peter, M., Kratzer, A., and Kalvius, G.M.: X-ray diffractometer for high pressure and low temperatures. Mater. Sci. Forum 79–82, 419–426 (1991).Google Scholar
Koga, E., Hogiri, M., and Higashi, Y.: Analysis of grain-boundary in SrCoO3–doped ZnO varistors and its electrical characteristics. Key Eng. Mater. 582, 181–184 (2014).Google Scholar
Takeda, Y., Kanto, R., Takada, T., and Yamamoto, O.: Phase relation and oxygen-non-stoichiometry of perovskite-like compound SrCoO x (2.29 < x < 2.80). Z. Anorg. Allg. Chem. 540/541, 259–270 (1986).Google Scholar
Quadir, T. and Readey, D.W.: Microstructure development of zinc oxide in hydrogen. J. Am. Ceram. Soc. 72(2), 297–302 (1989).Google Scholar
Schmidt, O., Kiesel, P., Walle, C.G.V.D., Johnson, N.M., Nause, J., and Dӧhler, G.H.: Effects of an electrically conducting layer at the zinc oxide surface. Jpn. J. Appl. Phys. 44, 7271–7274 (2005).Google Scholar
Furukawa, A., Ogasawara, N., Yokozawa, R., and Tokunaga, T.: Electron trap level of Cu-doped ZnO. Jpn. J. Appl. Phys. 47, 8799–8801 (2008).Google Scholar