Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference (한국전기전자재료학회:학술대회논문집)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Effect of Reduction-Reoxidation Firing on PTCR Properties of Sm-doped Barium Titanate Ceramics

Sm이 첨가된 티탄산바륨의 PTCR 특성에 대한 환원-재산화의 영향

  • Chun, Myoung-Pyo (Korea Institute of Ceramic Engineering and Technology (KICET)) ;
  • Myoung, Seong-Jae (Korea Institute of Ceramic Engineering and Technology (KICET)) ;
  • Han, Ik-Hyun (Korea Institute of Ceramic Engineering and Technology (KICET))
  • Published : 2005.11.10
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Abstract

The effect of reduction and re-oxidation firing on the PTCR properties of Sm-doped Barium Titanate ceramics was investigated for the application of multilayered PTC thermistor. The lattice parameter a, c decreases monotonically with increasing oxygen concentration in the reoxidation atmosphere, which seems to be related with the electrostatic Coulomb interaction between oxygen vancancy and nearest other atoms. With increasing oxygen concentration, the resistivity at room temperature and the magnitude of resistivity jump as a function of temperature increased in the region of oxygen concentration of 0 $\sim$ 10%. However, the resistivity at room temperature and the magnitude of resistivity jump is nearly constant and saturated in the region of oxygen concentration of 10 $\sim$ 20%. These phenomena is considered to be related with the variation of oxygen and barium-vancany concentration near the grain boundary.

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