Preparation and Electrical Properties of PTCR Ceramic Materials

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J. Korean Ceram. Soc. > Volume 22(2); 1985 > Article

Journal of the Korean Ceramic Society 1985;22(2): 11.

정저항요업체의 제조와 전기적 성질

정형진, 윤상옥

한국과학기술원 무기재료연구실

Preparation and Electrical Properties of PTCR Ceramic Materials

ABSTRACT

The semiconducting ceramics having positive temperature coefficient of resistivity in he family of 0.25mol% $Sb_2O_3$ doped barium titanates were prepared with AST ($4Al_2O_3$.$9SiO_2$.$3TiO_2$) and $MnO_2$ as additives and these electrical properties were investigated. The PTCR characteristic in these ceramic materials was improved by the addition of AST and $MnO_2$ because the addition of AST decreased the room temperature resistivity and controlled grin size due to the formation of a liquid phase during sintering and the addition of $MnO_2$ improved by forming acceptor level on the intergranular layer. On dependence on the switching time as switching temperature was increased the initial power and switching time increased.