ZHANG liping 1,2, ZHANG Fengqing 1, YANG shiju 1,GUO Xiaodong 3, FAN Suhua 3
(1.Shandong Jianzhu University, Jinan 250101, Shandong, China; 2. Shandong Co-Innovation Center of Grean Building, Jinan
250101, Shandong, China; 3. Shandong Women’s University, Jinan 250300, Shandong, China)
Abstract: (1-x)Sr2Bi4Ti5O18-xBiFeO3(SBFTi-x, x=0.1~0.4) composite ferroelectric films were prepared with Sr2Bi4Ti5O18 and BiFeO3, then the film samples were tested and studied. Compared to Sr2Bi4Ti5O18(SBTi) films, with the increasing of BFO content, the SBFTi-x ferroelectric films performed better in ferroelectrics. When the substitution amount of BFO was 0.3, in the field of 931 KV/cm, the remnant polarization and coercive field were 2Pr=23.4 μC/cm2 and 2Ec=28.0 KV/cm. With the increasing of BFO content, the leakage increased gradually; when the substitution amount of BFO was 0.3, the leakage current density was small. The linear fitting of the leakage current found that when the field is less than 230 KV/cm, all the fitting slopes are close to 1, which shows that the membrane leakage mechanism is prior to ohmic conduction (ɑ≈1); when the field is higher than 230 KV/cm, the conductive mechanism is FN tunneling.
Key words: Sr2Bi4Ti5O18; sol gel method; ferroelectric thin films; ferroelectric property