Pb(Zr_(0.52)Ti_(0.48))O_3/YBa_2Cu_3O_(7-x)双层结构电学特性研究

The electrical properties in Pb(Zr_(0.52)Ti_(0.48))O_3/YBa_2Cu_3O_(7-x) bilayers structure

该研究通过溶胶-凝胶结合PLD的方法,在LaAlO_3(LAO)基板上制备了具有良好的c轴取向的Pb(Zr_(0.52)Ti_(0.48))O_3/YBa_2Cu_3O_(7-x)(PZT/YBCO)双层薄膜。采用溅射法制备了Pt顶电极,在300K^50K温度范围内,对Pt/PZT/YBCO的电滞回线和J-V特性曲线进行研究,结果表明:300K时,Pt/PZT/YBCO的剩余极化强度约为22μC/cm^2,随着温度的降低,剩余极化强度基本保持不变同时矫顽场和临界导通电压(Vc)增大、漏电流减小,当YBCO进入超导态时,Vc随温度的变化规律发生改变。进一步研究了不同电压下Pt/PZT/YBCO的电流输运特性,当外加偏置电压较小时(临界导通电压以下),Pt/PZT/YBCO的电流输运特性主要符合欧姆导电机制,当外加偏置电压增大到临界导通电压以上时,电流输运特性主要符合肖特基发射机制。

Pb （ Zr0 52 Ti0.48 ） O3/YBa2 Cu3 O7 - x （ PZT/YBCO ） bilayer structures were prepared on LaA103 （LAO） substrate by sol - gel with PLD method. The PZT/YBCO exhibited a strong c - axis orientation. The Pt top electrode was prepared by sputtering, and the hysteresis loops and J - V characteristic curves of Pt/PZT/YBCO were studied in the temperature range of 300K - 50K. The results indicate that the residual polarization of Pt/PZT/YBCO is about 22μC/cm2 at 300K. With the decrease of the temperature, the residual polarization remain unchanged while the coercive field and the critical conduction voltage （Vc ） increase, and the leakage current decreases. The regulation of Vc with temperature changes suddenly at the superconducting transition temperature of YBCO. The current transport properties of Pt/PZT/YBCO were further investigated under different voltages in the range of 300K - 50K. Results show that the current transport characteristics of Pt/PZT/YBCO are mainly in accordance with Ohmic conduction mechanism when the voltage is relatively small（ lower than the Vc ）, and is mainly consistent with the schottky emission mechanism when the bias voltage is higher than the Vc.