Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Effect of Additives on the PTCR Characteristics of La3+ Doped(Ba1-xCax)TiO4 Ceramics

La3+ doped (Ba1-x Cax) TiO3의 PTCR 특성에 미치는 첨가제의 영향

  • Published : 1988.01.01
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Abstract

Commercially available PTCR (Postive Temperature Coefficient of Resistivity) ceramics which have low room temperature resistance, high PTC effect and temperature coefficient were prepared by La3+ doped semiconducting barium calcium titanate soild solutions. PTCR characteristics were remarkably improved by addition of AST (1/3 Al2O3$.$3/4SiO2$.$1/4TiO2) and MnCl2. That can be explained by formation of liquid phase during sintering and acceptor level on the intergranular layer. Resistivity anormaly increased with decreasing cooling rate. Optimum manufacturing conditions were cooling rate below 100$.$C/hr, Ca and Mn content of 4 mol% &, 0.09-0.12mol% respectively.

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References

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