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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La0.5Sr0.5CoO_3(LSCO)/Na_(0.5)Bi_(0.5)TiO_3(NBT)/LSCO(LSCO/NBT/LSCO)异质结铁电电容器。研究了Na_(0.5)Bi_(0.5)TiO_3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1 500 k V/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/cm2)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400 k V/cm时,LSCO/NBT/LSCO电容器满足欧姆导电机制,在电场大于400 k V/cm时,满足空间电荷限流传导机制。
The nanocrystalline La0.5Sr0.5CoO3 (LSCO) / Na0.5Bi0.5TiO3 (001) thin films were deposited on (001) Si substrate by RF magnetron sputtering and pulsed laser deposition with Ti-Al as the barrier layer NBT) / LSCO (LSCO / NBT / LSCO) Heterojunction Ferroelectric Capacitors. The structure and physical properties of Na_ (0.5) Bi_ (0.5) TiO_3 ferroelectric thin films were studied. The results show that the Ti-Al barrier layer has an amorphous structure and the NBT thin film has good crystal quality. The LSCO / NBT / LSCO capacitor exhibits a saturated hysteresis loop with a large remanent polarization (47.9μC / cm2) and a small pulse-width dependence at a driving electric field of 1 500 kV / cm, Fatigue and retention characteristics are good. In addition, the leakage mechanism studies show that the LSCO / NBT / LSCO capacitors satisfy the ohmic conduction mechanism when the applied electric field is less than 400 kV / cm, and space charge current-limiting conduction mechanism is satisfied when the electric field is greater than 400 kV / cm.