钛酸锶钡薄膜的制备及其铁电性能研究

Preparation and the Properties of Ba_(0.5)Sr_(0.5)TiO_3Ferroelectric Thin Films

本文采用溶胶-凝胶法(Sol-gel)制备Ba_(0.5)Sr_(0.5)TiO_3(BST)铁电薄膜,研究了在退火时间为450 s条件下,溶胶浓度、退火温度以及涂膜层数对薄膜的结晶结构和铁电性能的影响。利用X射线衍射分析仪(XRD)、铁电测试仪对BST薄膜的微观结构和电学性能进行了表征分析。结果表明:当溶胶浓度为0.4 mol/L,涂膜层数为4层,退火温度为650℃时,BST薄膜的矫顽场(EC)约为230 kV/cm,饱和极化值(PS)约为18μC/cm^2,剩余极化值(Pr)约为7.5μC/cm^2,表明薄膜具有良好的铁电性能。当电场强度为175 kV/cm时,BST薄膜达到饱和状态时而未被击穿,此时薄膜的电流密度J约为0.29μA/cm^2,表明所制备的薄膜质量较好。

Barium strontium titanate films with higher properties were obtained by sol- gel processing on Pt/TiO2/SiO2/Si substrate. And the influence of Solution concentration, coating layers and annealing temperature on the crystalline structure and electric properties of thin films was studied when the annealing time is 450s. By X-ray diffraction （XRD） and ferroelectric tester, the microstructure and ferroelectric properties were character- ized. The results show that, BST films have good ferroelectrie properties, the saturated polarization value with 18℃/cm2, the remaining polarization value with7.5μC/cm2, the Coercive field value with 230 kV/cm, when the annealing temperature is 650℃, the solution concentration is 0.4moL/L and the coating layers number is 4. In 175 kV/cm electric field, the current density J is about 0.29μA/cm2, indicating that the BST thin films can reach the saturation polarization state without breakdown.