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Dielectric Properties and Microstructure of BaTiO3 Ceramics

Published online by Cambridge University Press:  01 February 2011

Dae-Chul Park
Affiliation:
Advanced Materials Laboratory, National Institute for Materials Science Tsukuba, Ibaraki 305-0044 Japan
Jun-ichi Itoh
Affiliation:
Mitsui Mining & Smelting Co., LTD Ageo-shi, Saitama 362-0021 Japan
Isao Sakaguchi
Affiliation:
Advanced Materials Laboratory, National Institute for Materials Science Tsukuba, Ibaraki 305-0044 Japan
Naoki Ohashi
Affiliation:
Advanced Materials Laboratory, National Institute for Materials Science Tsukuba, Ibaraki 305-0044 Japan
Toyohiko Yano
Affiliation:
Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology Meguro, Tokyo 152-8550 Japan
Hajime Haneda
Affiliation:
Advanced Materials Laboratory, National Institute for Materials Science Tsukuba, Ibaraki 305-0044 Japan
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Abstract

Dielectric properties and microstructure were investigated in BaTiO3 ceramics with various additives, Ho2O3, MgO, Ho2O3/MgO, and La2O3. The dielectric constants were increased up to ∼4000 and ∼3000 at 25°C in the 1 mol% Ho-doped and 0.5 mol% Mg-doped BaTiO3 materials, respectively. The BaTiO3 material codoped with 3 mol% Ho + 1.5 mol% Mg led to increase dielectric constant up to ∼6000 at 25°C and the dielectric constant peak around Curie temperature was suppressed at temperature range of from 25°C to 125°C. The size of BaTiO3 grains depended on the content and kind of an additive. Core-shell grains and secondary phase were also dependent on an additive. Core-shell grains were formed completely in Ho-doped BaTiO3 except for 0.5 mol%, but the structure was little observed in Mg- and La-doped BaTiO3 material. Codoped BaTiO3 also formed the core-shell grains.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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