Effects of La2O3 and Ta2O5 on the PTCR Characteristics in Molten Salt Synthesized BaTiO3

용융염 합성법에 의한 BaTiO3의 PTCR특성에 미치는 La2O3와 Ta2O5의 영향

  • 윤기현 (연세대학교 요업공학과) ;
  • 김동영 (연세대학교 요업공학과) ;
  • 윤상옥 (연세대학교 요업공학과)
  • Published : 1988.03.01

Abstract

The effects of flux KCl and dopants, La2O3 and Ta2O5, on the PTCR characteristics in molten salt synthesized BaTiO3 have been studied. The resistivity of BaTiO3 at room temperature decreases with increasing amount of dopant La2O3 up to 0.2 atom%, and then increases with La2O3 content. In case of dopant Ta2O5, it increases with increasing amount ofthe dopant. These results could be explained by observation of the microstructure and defect equation. From the results of complex impedance-frequency characteristics, the grain resistances are almost same but the resistances at the grain boundary are quite different.

Keywords

References

  1. German Patent 929,350 Method of Preparation of Semiconducting Materials P.W. Haayman;R.W. Dam;H.A. Klans
  2. J. Am. Ceram. Soc. v.47 no.10 Resistivity Anormaly in Doped Barium Titanate W. Heywang
  3. Ceramic Materials for Electronics R.C. Buchanan
  4. IEEE Trans. Manuf. Tech. v.MFT-3 no.2 Ceramic Manufacturing Technology for the High Performance PTC Thermisters H. Ueoka;M. Yodogawa
  5. J. Am. Ceram. Soc. v.64 no.11 Effect of Microstructure on the PTCR Effect in Semiconducting Barium Titanate Ceramics M. Kuwabars
  6. Jpn. J. Appl. Phys. v.5 no.4 The Effects of Additives and of Ambient Atmosphere during Heating on Electrical Resistivity of Semiconducting BaTiO₃ T. Ashida;H. Toyoda
  7. Mat. Res. Bull. v.21 no.12 Influence of Synthesis Method of the PTCR Effect in Semiconducting BaTiO₃ K.H. Yoon;K.Y. Oh;S.O. Yoon
  8. High Tech. Ceramics, Mat. Sci. Monographs v.38B PTCR Effects in Semiconductive BaTiO₃Prepared in Molten KCI K.H. Yoon;E.H. Lee;P. Vincenzini(ed.)
  9. J. Kor. Ceram. Soc. v.24 no.6 PTCR Effects in $Nb_2O_5$ Doped BaTiO₃Ceramics Prepared By Molten Salt Synthesis Method K.H. Yoon;H.W. Cheong;S.O. Yoon
  10. ASTM Standard C-373-72
  11. Trans. J. Bull. Ceram. Soc. v.75 no.5 Effect of Addition on the Sinterability of Barium Titanate M.N. Swilam;A.M. Gudalla
  12. J. Am. Ceram. Soc. v.67 no.4 Defect Chemistry of Donor Doped BaTiO₃ N.H. Chan;D.M. Smith
  13. J. Am. Ceram. Soc. v.69 no.6 Compensating Defects in Highly Donor Doped BaTiO₃ H.M. Chan;M.P. Harmer;D.M. Smith
  14. J. Am. Ceram. Soc. v.56 no.6 Effect of Rare-Earth Ions on Electrical Conductivity of BaTiO₃Ceramics T. Murakami;T. Miyashita;M. Nakahara;E. Sekine
  15. J. Am. Ceram. Soc. v.49 no.6 Ferroelectrics of Ultrafine Particle Size: Ⅱ. Grain Growth Inhibition Studies T.M. Harkulich;J. Magder;M.S. Vukasovich
  16. Yogyo-Kyokai-Shi v.95 no.9 N. Shikatani;Y. Kumamoto;M. Nagano
  17. J. Am. Ceram. Soc. v.50 no.9 Inhibition of Grain Growth in Barium Titanate D.A. Payne;H.U. Anderson
  18. J. Am. Ceram. Soc. v.71 no.1 Compensation in Semiconducting Barium Titanate C.J. Peng;H.Y. Lu
  19. Trans. Far. Soc. v.42A Permittivity of Polycrystals of the Perovskite Type D.F. Rushman;M.A. Strivens
  20. Solid State Commu. v.64 no.4 Contact Resistance of the Electrodes of the Semiconducting Ceramics S.O. Yoon;H.J. Jung;K.H. Yoon