Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
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Preparation of Ferroelectric Barium Titanate Fine Particles by Hydrothermal Method and Their Dielectric Properties -Variation of Dielectric Properties and Phase Transition by Heat Treatment-

강유전성 티탄산바륨 극미립자의 수열합성과 그 유전특성 - 열처리에 의한 상전이 및 유전 특성 변화 -

  • Um, Myeong-Heon (Department of Industrial Chemistry, Cheonan National Technical College) ;
  • Lee, Jin-Sik (Department of Chemical Engineering, Dankook University) ;
  • Lee, Chul-Tae (Department of Chemical Engineering, Dankook University)
  • 엄명헌 (국립천안공업대학 공업화학과) ;
  • 이진식 (단국대학교 공과대학 화학공학과) ;
  • 이철태 (단국대학교 공과대학 화학공학과)
  • Received : 1998.03.19
  • Accepted : 1998.06.16
  • Published : 1998.11.10
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Abstract

$BaTiO_3$ particles were prepared using $Ba(OH)_2{\cdot}8H_2O$ and $Ti(OC_2H_5)O_4$ by the hydrothermal method and their characteristics treated at the various temperatures have been investigated. This prepared $BaTiO_3$ powder includes a very small amount of $H_2O$ and $OH^-$. By increasing the treated temperature from $200^{\circ}C$ to $1000^{\circ}C$, the mean particle size was accordingly increased from $0.022{\mu}m$ to $0.072{\mu}m$ and the tetrogonality(c/a)was increased from 1.02 to 1.2 so that the phase transition to tetroganal takes place. $BaTiO_3$ sintered at $1250^{\circ}C$ after heat treatment at $400^{\circ}C$ for 3 hrs showed a specific dielectric constant of 8120 and surface activation energy was 9680 kcal/mol.

$Ba(OH)_2{\cdot}8H_2O$와 $Ti(OC_2H_5)O_4$를 사용하여 고순도 $BaTiO_3$ 분말을 수열 합성법으로 제조하고 열처리 온도에 따른 분말 특성을 조사하였다. 이때 제조된 분말 내에는 미량의 $H_2O$ 및 $OH^-$가 존재함을 확인할 수 있었으며 열처리 온도가 $200^{\circ}C$에서 $1000^{\circ}C$로 증가할수록 $BaTiO_3$의 평균입경은 $0.022{\mu}m$에서 $0.072{\mu}m$로 증가되었고 tetrogonality(c/a)도 1.02에서 1.2로 증가되어 정방정 형태로 상전이가 나타났다. 또한 $400^{\circ}C$로 3시간 동안 열처리한 후 이들 분말들을 $1250^{\circ}C$로 소결할 때 8120의 비유전율값이 얻어졌으며 표면 활성화 에너지값은 9680 kcal/mol이었다.

Keywords

Acknowledgement

Supported by : 한국학술진흥재단

References

  1. Rep. Prog. Phys. v.52 R. E. Newnham
  2. Am. Ceram. Soc. Bull. v.71 L. M. Sheppard
  3. J. Am. Ceram. Soc. v.75 T. Ishihara;K. Kometani;Y. Mizuhara;Y. Takita
  4. J. Am. Ceram. Soc. v.46 P. K. Gallagher;F. Schrey;F. V. Dikarcello
  5. J. Am. Ceram. Soc. v.77 Y. Suyama;M. Nagasawa
  6. Mater. Res. Bull. v.23 K. W. Kirby
  7. J. Eur. Ceram. Soc. v.9 D. Hennings;S. Schreinemacher
  8. J. Ceram. Sco. Jap. v.103 S. Wada;R. Suzuki;T. Noma
  9. J. Am. Ceram. Soc. v.77 H. J. Schmutzler;M. M. A ntony;K. H. Sandhage
  10. J. Am. Ceram. Soc. v.42 L. K. Templeton;J. A. Pask
  11. J. Am. Ceram. Soc. v.78 M. M. Lencka;A. Anderko;R. E. Riman
  12. J. Am. Ceram. Soc. v.78 R. P.S. M. Lobo;N. D. S. Mohallem;R. L. Moreira
  13. The 2nd Korea-Japan Symposium on Advanced Materials H. Kumazawa;M. H. Um
  14. J. Ind. & Eng. Chem. Kor. v.3 M. H. Um;C. T. Lee;H. Kumazawa
  15. Handbook of Chemistry and Physics(55th ed.) R. C. Weast(Ed.)
  16. Principles of Extractive Metallurgy F. Habashi
  17. J. Am. Ceram. Soc. v.71 W. Hertl