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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: seokhyun72.yoon@samsung.com
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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

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