Effects of Nb2O5 and MnO2 on the PTCR behavior of Lead-free Ba0.99(Bi1/2Na1/2)0.01TiO3 Ceramics

무연 Ba0.99(Bi1/2Na1/2)0.01TiO3 세라믹의 PTCR 특성에 미치는 Nb2O5와 MnO2의 효과

  • 박용준 (고려대학교 신소재공학과) ;
  • 남산 (고려대학교 신소재공학과) ;
  • 이영진 (요업기술원 전자부품팀) ;
  • 정영훈 (요업기술원 전자부품팀) ;
  • 백종후 (요업기술원 전자부품팀) ;
  • 김대준 ((주)하이엘 기술연구소) ;
  • 이우영 ((주)하이엘 기술연구소)
  • Published : 2008.07.01


The effects of $Nb_2O_5$ and $MnO_2$ on the positive temperature coefficient of resistivity (PTCR) behavior of lead-free $Ba_{0.99}(Bi_{1/2}Na_{1/2})_{0.01}TiO_3$ (BaBiNT) ceramics were investigated in order to fabricate a PTC thermistor available at high temperature of > $120^{\circ}C$. In particular, 0.05 mol% $Nb_2O_5$ added BaBiNT ceramic, which has significantly increased Curie temperature (Tc) of $160^{\circ}C$, showed good PTCR behavior; low resistivity at room temperature $(\rho_r)$ of $80.1{\Omega}{\cdot}cm$, a high $\rho_{max}/\rho_{min}$ ratio of $5.65{\times}10^3$ and a large resistivity temperature factor (a) of 18.5%/$^{\circ}C$. Furthermore, the improved $\rho_{max}/\rho_{min}$ of $6.48{\times}10^4$ and a of 25.4%/$^{\circ}C$ along with higher $T_c$ of $167^{\circ}C$ despite slightly increased $\rho_r$ of $569{\Omega}{\cdot}cm$, could be obtained for the BaBiNT + 0.05 mol% $Nb_2O_5$ + 0.02 wt% $MnO_2$ ceramic cooled down at a rate of $200^{\circ}C/h$.


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