Influence of Ca on Structural and Ferroelectric Properties of Laser Ablated SrBi2Ta2O9 Thin Films
Influence of Ca on Structural and Ferroelectric Properties of Laser Ablated SrBi2Ta2O9 Thin Films
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Ca 对激光烧蚀 SrBi2Ta2O9 薄膜结构和铁电性能的影响
DOI：
10.1143/jjap.42.162
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发表时间：
2003
影响因子：
1.5
通讯作者：
R. Katiyar
中科院分区：
文献类型：
--
作者：
R. Das;P. Bhattacharya;W. Pérez;R. Katiyar
采用脉冲激光沉积技术制备了x=0、0.1、0.2和0.3的Sr1-xCaxBi2Ta2O9 （SCBT）铋层状钙钛矿。研究了Ca对SrBi2Ta2O9 （SBT）薄膜结构和铁电性能的影响。XRD分析表明，经750℃退火后的SCBT薄膜为多晶。SBT薄膜晶格参数随Ca含量的增加而减小，这是由于Ca在sr位的离子半径变小所致。原子力显微镜观察到，随着Ca浓度的增加，晶粒尺寸和表面粗糙度增大。掺钙20%的SBT薄膜铁电性能增强，残余极化（Pr）达到23.8µC/cm2。在sr位加入Ca后，SBT薄膜中Pr的抗疲劳性能下降。SBT中矫顽力场随Ca含量的增加而增大。SBT薄膜的介电常数随晶粒尺寸的增大而增大。随着Ca的掺入，SCBT薄膜的漏电流密度增大。
Bismuth layered perovskites of composition Sr1-xCaxBi2Ta2O9 (SCBT) with x=0, 0.1, 0.2, and 0.3 were grown using pulsed laser deposition technique. Influence of Ca on the structural and ferroelectric properties of SrBi2Ta2O9 (SBT) thin films have been investigated. XRD analysis revealed that SCBT thin films were polycrystalline after annealing at 750°C. The decrease in lattice parameter with increasing Ca contents in SBT thin films was attributed to smaller ionic radii of Ca at Sr-site. The grain size and the surface roughness were increased with higher Ca concentration as observed by atomic force microscopy. SBT thin films with 20% Ca doping exhibited enhanced ferroelectric properties with a remanent polarization (Pr) of 23.8 µC/cm2. The fatigue resistance of Pr in SBT thin films degraded upon Ca incorporation at Sr-site. The coercive field increased with increases in Ca contents in SBT. The dielectric constant of SBT thin films was increased with the increase in grain size. The leakage current density of the SCBT thin films increased upon Ca incorporation.