Effects of Pb(Zr0.52Ti0.48)O-3 polarization on the YBa2Cu3O7-x electrical transport and magnetization
Effects of Pb(Zr0.52Ti0.48)O-3 polarization on the YBa2Cu3O7-x electrical transport and magnetization
复制标题
Pb(Zr0.52Ti0.48)O-3 极化对 YBa2Cu3O7-x 电输运和磁化强度的影响
DOI：
10.1088/2053-1591/aa5bfe
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发表时间：
2017
影响因子：
2.3
通讯作者：
Lei Li
中科院分区：
文献类型：
--
作者：
Jia Jiqiang;Zhao Gaoyang;Lei Li
采用溶胶-凝胶法在LaAlO 3（LAO）衬底上制备了厚度为70 nm的YBa 2Cu 3 O 7− x（YBCO）超导薄膜，并对薄膜中的Pb采用脉冲激光沉积（PLD）法生长了具有界面共格结构的（Zr0.52Ti0.48）O3（PZT）铁电薄膜，然后在PZT薄膜上用直流溅射法沉积Pt上电极，得到Pt/PZT/YBCO三层结构。在50-300 K温度范围内研究了YBCO的铁电滞回特性以及PZT的铁电极化场对YBCO电性能和磁化强度的影响。结果表明，随着温度的降低，Pt/PZT/YBCO复合材料的反射极化几乎保持不变，矫顽场增大。由于PZT极化的影响，YBCO的R-T曲线上移（正极化）或下移（负极化），表明PZT的铁电极化调制了YBCO的R-T曲线。当YBCO处于超导态时，随着PZT极化强度的增加，YBCO的磁化强度减小，说明PZT的极化场对YBCO的磁化强度有调制作用。进一步研究了Pt/PZT/YBCO的J-V曲线，发现Pt/PZT/YBCO存在一个阈值导通电压Vt，当外加偏压低于Vt时，Pt/PZT/YBCO的漏电流很小，当外加偏压高于Vt时，漏电流迅速增大。同时，Vt随温度的降低而增大，在YBCO的超导转变温度处发生明显变化。
The YBa 2 Cu 3 O 7− x (YBCO) superconducting film of 70 nm thickness was prepared on a LaAlO 3 (LAO) substrate via the sol–gel method, following which the Pb (Zr 0.52 Ti 0.48) O 3 (PZT) ferroelectric film possessing interfacial coherent structure was grown via pulsed laser deposition (PLD) method, and then the Pt top electrode was deposited onto the PZT film by DC sputtering, resulting in the Pt/PZT/YBCO tri-layer structure. The ferroelectric hysteresis characteristics and the effects of ferroelectric polarization field of PZT on the electrical properties and magnetization of YBCO were studied for the temperature range of 50–300 K. Results reveal that as the temperature decreases, the remanent polarization of Pt/PZT/YBCO remains nearly constant, while the coercive field increased. The R–T curve of YBCO shifts upwards (positive polarization) or downwards (negative polarization) due to the influence of PZT polarization, indicating that the ferroelectric polarization of PZT modulates the R–T curve of YBCO. When YBCO is in the superconducting state, the magnetization of YBCO decreases with increasing polarization of PZT, indicating that the polarization field of PZT has a modulation effect on the magnetization of YBCO. Further investigation on the J–V curve of Pt/PZT/YBCO revealed a threshold conduction voltage (V t) and when the applied bias voltage was lower than V t, the leakage current of Pt/PZT/YBCO was small, and when the applied voltage was higher than V t, the leakage current rapidly increased. Meanwhile, the V t increased with decreasing temperature and then markedly changes at the superconducting transition temperature of YBCO.