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采用优化的溶胶-凝胶(Sol-gel)技术,同一工艺条件下在Pt/TiO2/SiO2/Si衬底上成功地制备了Bi3.25La0.75Ti3O12(BLT)和Bi3.15Nd0.85Ti3O12(BNT)铁电薄膜.X射线衍射(XRD)测试表明BLT和BNT薄膜具有单相的取向随机的多晶微结构;扫描电镜(SEM)的观测显示了这些薄膜具有50~100nm晶粒构成的均匀致密的表面形貌.利用铁电测试仪测定了以Cu为上电极而形成的金属-铁电薄膜-金属结构的电容器的铁电性能,得到了很好的饱和电滞回线.在最大外加场强为400kV/cm时,BLT和BNT薄膜的剩余极化强度(2Pr)和矫顽电场(2Ec)分别为25.1μC/cm2,203kV/cm和44.2μC/cm2,296kV/cm.疲劳测试表明,在1MHz频率测试下经过1.75×1010次读写循环后,由BLT和BNT薄膜组成的电容器几乎没有表现出疲劳,呈现很好的抗疲劳特性.分析比较了La和Nd掺杂对薄膜结构及铁电性能的影响及其机理.
Bi3.25La0.75Ti3O12 (BLT) and Bi3.15Nd0.85Ti3O12 (BNT) were successfully prepared on the Pt / TiO2 / SiO2 / Si substrate under the same process conditions by using the optimized sol- The results of X-ray diffraction (XRD) show that the BLT and BNT films have a single-phase random polycrystalline microstructure. Scanning electron microscopy (SEM) observations show that these films have a uniform and compact Surface morphology.The ferroelectric properties of a metal-ferroelectric thin film-metal structure capacitor with Cu as the upper electrode were measured by a ferroelectric tester, and a good saturation hysteresis loop was obtained.At the maximum applied field strength The remanent polarization (2Pr) and coercive electric field (2Ec) of BLT and BNT films were 25.1μC / cm2, 203kV / cm and 44.2μC / cm2, 296kV / cm at 400kV / The capacitors composed of BLT and BNT films showed almost no fatigue and showed good anti-fatigue properties after 1.75 × 1010 read and write cycles at 1MHz frequency.Analysis of the effect of La and Nd doping on the structure of thin films and ferroelectric Influence of performance and its mechanism.