中文摘要：

通过射频磁控溅射法和脉冲激光沉积法，以Ti—Al为阻挡层，在（001）Si衬底上制备了La0.5Sr0.5CoO3（LSCO）／Na0.5Bi0.5TiO3（NBT）／LSCO（LSCO／NBT／LSCO）异质结铁电电容器。研究了Na0.5Bi0.5TiO3铁电薄膜的结构和物理性能。结果表明：Ti—Al阻挡层为非晶结构，NBT薄膜结晶质量良好。在1500kV／cm驱动电场下，LSCO／NBT／LSCO电容器呈现饱和的电滞回线，具有较大的剩余极化强度（47．9μC／cm^2）和较小的脉宽依赖性，而且抗疲劳特性和保持特性良好。此外，漏电机制研究表明：当外加电场小于400kV／cm时，LSCO小BT／LSCO电容器满足欧姆导电机制，在电场大于400kV／cm时，满足空间电荷限流传导机制。

英文摘要：

La0.5Sr0.5CoO3（LSCO）/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 （LSCO/NBT/LSCO） ferroelectric capacitor heterostructure was fabricated on （001）Si substrate with amorphous Ti-Al film as a diffusion barrier layer, in which the LSCO and Ti-A1 films both were prepared by magnetron sputtering （MS）, and the NBT was prepared by a pulsed laser deposition method （PLD）. The structural and physical properties of Na0.5Bi0.5TiO3 film were characterized. The results show that the Ti-Al barrier is amorphous, and the NBT film consists of the crystallines. The LSCO/NBT/LSCO capacitor presents a saturated hysteresis loop, a high remnant polarization （i.e., 47.9 μC/cm^2）, a small pulse width dependence, good fatigue and retention characteristics at an applied field of 1 500 kV/cm. Moreover, the leakage mechanism of the LSCO/NBT/LSCO ferroelectric capacitor was investigated. The LSCO/NBT/LSCO capacitor has the Ohm conduction behavior at applied fields of 〈 400 kV/cm and bulk-limited space charge-limited conduction （SCLC） at the applied fields of〉 400 kV/cm.