Microstructure and Dielectric Properties of a SrTiO3-based GBL Capacitor

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J. Korean Ceram. Soc. > Volume 24(3); 1987 > Article

Journal of the Korean Ceramic Society 1987;24(3): 270.

SrTiO3계 GBL Capacitor의 미세구조 및 유전특성

천채일, 김호기

한국과학기술원 재료공학과

Microstructure and Dielectric Properties of a SrTiO3-based GBL Capacitor

ABSTRACT

The microstructure and dielectric properties of a SrTiO3-based GBL (Grain Boundary Layer) capacitor were investigated. The 0.6 mol% Nb2O5 doped SrTiO3 was sintered for 3 hr at 1450$^{circ}C$ in mixed gas(N2/H2) atmosphere. The Nb2O5 promoted the grain growth of the SrTiO3 ceramics was decreased with the amount of Nb2O5. The oxide mixture(PbO, Bi2O3, B2O3) were painted on the reduced specimen and fired at 1000$^{circ}C$ to 1100$^{circ}C$ in air. The penetrated oxide mixture into specimen were located in grain boundaries. A SrTiO3-based GBL capacitor had the apparent permittivity of about 3.0${times}$104, the dielectric loss of 0.01-0.02, and insulating resistance of 108-109$Omega$.cm. The capacitor had the stable temperature coefficient of capacitance and exhibited dielectric dispersion over 107 Hz. The capacitance-voltage measurements indicated that the grain boundary was composed of the continuous insulating layers.