Dielectric Temperature Characteristics of Cerium‐Modified Barium Titanate Based Ceramics with Core—Shell Grain Structure

Journal of the American Ceramic Society - Tập 80 Số 1 - Trang 106-112 - 1997
Yung Park1, Ho‐Gi Kim2,3
1Department of Advanced Materials Engineering, Korea Advanced Institute of Science and Technology, Cheongryang, Seoul, Korea
2Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Kusong-dong, Yusong-gu, Taejon, Korea
3*Member, American Ceramic Society.

Tóm tắt

Various particle sizes of starting barium titanate were used to investigate the effect of chemical inhomogeneity on the dielectric temperature characteristics of a dilute solid solution of cerium‐modified barium titanate. Transmission electron microscopy and energy dispersive spectroscopy confirmed three distinct areas in the modified barium titanate: a grain core, a grain shell, and gradient regions. The grain size and volume fractions of the grain core were somewhat proportional to the particle size of the starting barium titanate. The dielectric temperature characteristics will be explained in the present paper in terms of the three inhomogeneous regions. Actually, the dielectric temperature characteristics of the large grains (3μm) proved to be a function of variation in the Tc values, whereas those of the small grains (,3μm) were a function of both the Tc values and the internal stress.

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