9. Dielectric Properties of Nm-Sized Barium Titanate Fine Particles and Their Size Dependence

  1. Sheng Yao,
  2. Bruce Tuttle,
  3. Clive Randall and
  4. Dwight Viehland
  1. Satoshi Wada,
  2. Takuya Hoshina,
  3. Hiroaki Yasuno,
  4. Masanori Ohishi,
  5. Hirofumi Kakemoto,
  6. Takaaki Tsurumi and
  7. Masatomo Yashima

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291252.ch9

Advances in Electronic Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 26, Number 5

Advances in Electronic Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 26, Number 5

How to Cite

Wada, S., Hoshina, T., Yasuno, H., Ohishi, M., Kakemoto, H., Tsurumi, T. and Yashima, M. (2005) Dielectric Properties of Nm-Sized Barium Titanate Fine Particles and Their Size Dependence, in Advances in Electronic Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 26, Number 5 (eds S. Yao, B. Tuttle, C. Randall and D. Viehland), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291252.ch9

Author Information

  1. Tokyo Institute of Technology 2-12-1 Ookayama Meguro, Tokyo, 152-8552

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982350

Online ISBN: 9780470291252

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Keywords:

  • dielectric constant;
  • ferroelectrics;
  • nanoparticles;
  • decomposition;
  • decomposition

Summary

The powder dielectric measurement of barium titanate (BaTiO3) fine particles with sizes from 17 to 1,000 nm revealed the maximum dielectric constant at a certain particle size. Moreover, the sizes with maximum dielectric constants were strongly dependent on the preparation methods. When the BaTiO3 fine particles were prepared using the original 2-step thermal decomposition method, a dielectric constant maximum of 15,000 was observed at 70 nm particle size. On the other hand, when the BaTiO3 fine particles were prepared using the modified 3-step thermal decomposition method, a dielectric constant maximum of 5,000 was observed at 140 nm. The former BaTiO3 was prepared in vacuum of 10−2 torr while the latter BaTiO3 was prepared in air. Structure refinement of BaTiO3 particles using a Rietveld method revealed that all of BaTiO3 particles were always composed of two parts; (a) surface cubic layer and (b) bulk tetragonal layer. Moreover, a thickness of surface cubic layer for BaTiO3 nanoparticles prepared in vacuum of 10−2 torr was much thinner than that for BaTiO3 nanoparticles prepared in air. Thus, to explain these differences, a new model on the basis of “surface relaxation” was proposed.