Electrode Dependence of Asymmetric Behavior of (La,Sr)CoO₃/Pb(Zr,Ti)O₃/(La,Sr)CoO₃ Thin Film Capacitors

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J. Korean Ceram. Soc. > Volume 35(7); 1998 > Article

Journal of the Korean Ceramic Society 1998;35(7): 647.

(La,Sr)CoO₃/Pb(Zr,Ti)O₃/(La,Sr)CoO₃박막 캐패시터의 비대칭성의 전극 의존성

최치홍, 이재찬, 박배호, 노태원

Electrode Dependence of Asymmetric Behavior of (La,Sr)CoO₃/Pb(Zr,Ti)O₃/(La,Sr)CoO₃ Thin Film Capacitors

ABSTRACT

(La,Sr)CoO3/Pb(Zr,Ti)O3/(La,Sr)CoO3 (LSCO) heterostructures have been grown on LaAlO3 substrates by pulsed laser deposition (PLD) to investigate asymmetric polarization of Pb(Zr,Ti)O3 (PZT) thin flims with different electrode configuration. P-V hysteresis loop of LSCO/PZT/LSCO was symmetric. However, LaCoO3 (LCO_/PZT/LSCO showed a largely asymmetric P-V hystersis loop and large relaxation of the remanent polarization at the negatively poled state, which means that the negatively poled state was unstable. On the other hand, LSCO/PZT/LCO exhibited large relaxation of the positively poled state. The asymmetric behavior of the polarized states implies the presence of an interal electric firld inside the PZT layer. It is suggested that internal electric field is caused by built-in voltages at LCO/PZT and LSCO/PZT interfaces. The built-in voltages at LCO/PZT and CSCO/PZT interfaces were 0.6 V and -0.12 V, respectively.

Key words: PZT capacitor, Imprint, Asymmetric, Built-in voltage