溶胶-凝胶法制备BaTiO3/SrTiO3多层膜的介电增强效应

采用溶胶凝胶法,在PtTiSiO2Si衬底上逐层制备了BaTiO3SrTiO3多层膜.从多层膜的XRD图可看出明显的双峰,分别对应为BaTiO3和SrTiO3的特征峰,表明样品已形成了多层膜结构.与同厚度的Ba05Sr05TiO3单层膜比较,BaTiO3SrTiO3多层膜的介电系数得到了明显的增强,在频率为10kHz时,周期为66nm的BaTiO3SrTiO3多层膜相对于同厚度的Ba05Sr05TiO3薄膜的介电系数从245增强到595,而损耗依然保持较低,分别为0029和0033.研究同时表明,BaTi关键词：溶胶-凝胶法多层膜介电增强

Dielectric enhancement in sol-gel derived BaTiO3/SrTiO3 multilayered thin films

Polycrystalline BaTiO 3/SrTiO 3 multilayered thin films have been prepared on Pt/Ti/SiO 2/Si substrates by a sol-gel processing.The X-ray diffraction patterns were composed of two sets of lines,one for BaTiO 3 and the other for SrTiO 3,indicating that the multilayered thin films were formed.The dielectric constant of the multilayered films was significantly enhanced and the dielectric loss kept low,compared with that of Ba 0.5Sr 0.5TiO 3 thin films.A maximum dielectric constant of 595 at 10kHz was observed for a stacking periodicity of 66nm at room temperature and the corresponding dielectric loss was kept low at 0.033.The study indicated that there are small differences between the multilayered films and the uniform films on the dielectric constant frequency dispersion,C-V characteristics and the dielectric constant-temperature relation.