Highfield effects of layered perovskite ferroelectric thin films

Highfield effects of ferroelectric thin films were studied, taking the system of sandwich structure Pt/Sr-Bi₂Ta₂O₉/Pt (Pt/SBT/Pt) film capacitor as an example. The characterizations and mechanism of leakage current, breakdown and current transient phenomena of ferroelectric thin films were discussed in detail under high electric field. It is found that leakage current mechanism of the films is from space-charge conduction to electrode injection with electric field increasing, that breakdown field of the films has a negative linear variation with the log of the electrode area, and that the characteristics of current transient in the films are not dependent on the polarization reverse. The theoretical analyses were consistent with experimental results.