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Effect of the pyrochlore (Y2Ti2O7) phase on the resistance degradation in yttrium-doped BaTiO3 ceramic capacitors

Published online by Cambridge University Press:  31 January 2011

Seok-Hyun Yoon*
Affiliation:
MLCC R&D Group, LCR Division, Samsung Electro-Mechanics Co., Ltd., Suwon, Gyunggi-Do, 443-743 Korea
Young-Sun Park
Affiliation:
MLCC R&D Group, LCR Division, Samsung Electro-Mechanics Co., Ltd., Suwon, Gyunggi-Do, 443-743 Korea
Jeong-Oh Hong
Affiliation:
MLCC R&D Group, LCR Division, Samsung Electro-Mechanics Co., Ltd., Suwon, Gyunggi-Do, 443-743 Korea
Dong-Sook Sinn
Affiliation:
MLCC R&D Group, LCR Division, Samsung Electro-Mechanics Co., Ltd., Suwon, Gyunggi-Do, 443-743 Korea
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Degradation of insulation resistance due to the formation of the Y2Ti2O7 (pyrochlore) phases in yttrium(Y)-doped BaTiO3 ceramics was investigated. The addition of Y2O3 and sintering aid SiO2 to the BaTiO3 ceramics caused the formation of barium-related BaSiO3 and titanium-related Y2Ti2O7 second phases. The appearance of the abnormally grown large pyrochlore grains with the increase of sintering temperature critically degraded insulation resistance at high temperatures. When the volume fraction of the pyrochlore phase increased, the resistance degradation was also observed although the grain size of the pyrochlore phase became smaller. The highly oxygen ionic conductive nature of the Y2Ti2O7 pyrochlore phase is supposed to accelerate electromigration of oxygen vacancies resulting in the resistance degradation. The formation of pyrochlore phase should be prevented to guarantee the high-temperature reliability of BaTiO3 bases ceramic capacitors.

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Articles
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1Waser, R., Baiatu, T.Härdtl, K.H.: DC electrical degradation of perovskite-type titanates: I. Ceramics. J. Am. Ceram. Soc. 73, 1645 1990CrossRefGoogle Scholar
2Waser, R., Baiatu, T.Härdtl, K.H.: DC electrical degradation of perovskite-type titanates: II. Single crystal. J. Am. Ceram. Soc. 73, 1654 1990Google Scholar
3Yang, G.Y., Dicky, E.C., Randall, C.A., Randall, M.S.Mann, L.A.: Modulated and ordered defect structures in electrically degraded Ni/BaTiO3 multilayer ceramic capacitors. J. Appl. Phys. 94, 5990 2003Google Scholar
4Kishi, H., Mizuno, Y.Chazono, H.: Base-metal electrode-nultilayer ceramic capacitors: Past, present and future perspectives. Jpn. J. Appl. Phys., Part 1 42, 1 2003CrossRefGoogle Scholar
5Zhi, J., Chen, A., Zhi, Y., Vilarinho, P.M.Baptista, J.L.: Incorporation of yttrium in barium titanate ceramics. J. Am. Ceram. Soc. 82, 1345 1999CrossRefGoogle Scholar
6Makovec, D., Samardzija, Z.Drofenik, M.: Solid solubility of holmium, yttrium, and dysprosium in BaTiO3. J. Am. Ceram. Soc. 87, 1324 2004Google Scholar
7Kramer, S., Spears, M.Tuller, H.L.: Conduction in titanate pyrochlores—Role of dopants. Solid State Ionics 72, 59 1994Google Scholar
8Yamaguchi, S., Kobayashi, K., Abe, K., Yamazaki, S.Iguchi, Y.: Electrical conductivity and thermoelectric power measurements of Y2Ti2O7. Solid State Ionics 113–115, 393 1998CrossRefGoogle Scholar
9Yoo, H.I., Song, C.R.Lee, D.K.: BaTiO3–δ: Defect structure, electrical conductivity, chemical diffusivity, thermoelectric power, and oxygen nonstoichiometry. J. Electroceram. 8, 5 2002Google Scholar
10Hagenbeck, R., Schneider-Stormann, L.S., Vollmann, M.Waser, R.: Numerical simulation of the defect chemistry and the electrostatics at grain boundaries in titanate ceramics. Mater. Sci. Eng., B B39, 179 1996Google Scholar
11Sasaki, K.Maier, J.: Low-temperature defect chemistry of oxides. I. General aspects and numerical calculations. J. Appl. Phys. 86, 5422 1999Google Scholar
12Hennings, D.F.K., Janssen, R.Reynen, P.J.L.: Control of liquid-phase-enhanced discontinuous grain growth in barium titanate. J. Am. Ceram. Soc. 70, 23 1987Google Scholar
13Kang, M.K., Yoo, Y.S., Kim, D.Y.Hwang, N.M.: Growth of BaTiO3 seed grains by the twin-plane reentrant edge mechanism. J. Am. Ceram. Soc. 83, 385 2000Google Scholar
14Yoon, S.H., Lee, J.H., Kim, D.Y.Hwang, N.M.: Effect of the liquid-phase characteristic on the microstructures and dielectric properties of donor-(niobium) and acceptor- (magnesium). Doped Barium Titanate. J. Am. Ceram. Soc. 86, 88 2003Google Scholar
15Kim, Y.M., Hong, S.H.Kim, D.Y.: Anisotropic abnormal grain growth in TiO2/SiO2-doped alumina. J. Am. Ceram. Soc. 83, 2809 2000Google Scholar
16Hong, S.H.Kim, D.Y.: Effect of liquid content on the abnormal grain growth of alumina. J. Am. Ceram. Soc. 84, 1597 2001Google Scholar
17Kim, B.K., Hong, S.H., Lee, S.H., Kim, D.Y.Hwang, N.M.: Sintering of alumina containing small amounts of a liquid phase. J. Am. Ceram. Soc. 86, 634 2003Google Scholar
18Tsur, Y., Dunbar, T.D.Randall, C.A.: Crystal and defect chemistry of rare earth cations in BaTiO3. J. Electroceram. 7, 25 2001CrossRefGoogle Scholar
19Wang, Y., Li, L., Qi, J.Gui, Z.: Ferroelectric characteristics of ytterbium-doped barium zirconium titanate ceramics. Ceram. Int. 28, 657 2002CrossRefGoogle Scholar
20Sato, S., Fujikawa, Y.Terada, Y.: Dielectric ceramic composition and electronic device. U.S. Patent No. 6 403 513, B1 2002Google Scholar