Effect of the Frit of the 2nd Firing Oxide in <TEX>$SrTiO_3$</TEX>-Based GBLC on the Dielectric Properties

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J. Korean Ceram. Soc. > Volume 28(4); 1991 > Article

Journal of the Korean Ceramic Society 1991;28(4): 261.

$SrTiO_3$계 Grain Boundary Layer Capacitor에서 2차 열처리 산화물의 Frit화가 유전적 성질에 미치는 영향

유재근, 최성철, 이응상

한양대학교 무기재료공학과

Effect of the Frit of the 2nd Firing Oxide in $SrTiO_3$-Based GBLC on the Dielectric Properties

ABSTRACT

The dielectric properties and microstructure of SrTiO3-based grain boundary layer (GBL) capacitor were investigated, and SrTiO3 GBL capacitor was made by penetrating the Frit (PbO-Bi2O3-B2O3 system). The Nb2O5-doped SrTiO3 ceramics were fired for 4-hours, at 145$0^{circ}C$ in H2-N2 atomsphere to get semiconductive ceramics. The grain size of SrTiO3 sintered at reduction atmosphere had increased as the amount of Nb2O5 increases and then decreased as the amount of Nb2O5 exceeded 0.2 mole%. Insulating reagents which contained PbO-Bi2O3-B2O3 system frit and oxide mixture were printed on the each semiconductive ceramics and fired at varying temperature and for different holding time. The optimum dielectric properties could be obtained by second heat treatment at 110$0^{circ}C$ for 1 hour, when frit paste was printed. A SrTiO3-based GBLC had the apparent permitivity of about 3.2$times$104, the dielectric loss of 0.01~0.02 and the stable temperature coefficient of capacitance. The influence of frit paste on dielectric properties was similiar to that of oxide paste but the stability of temperature property of capacitance was improved.