Properties of La-substituted Na0.5Bi4.5Ti4O15 ferroelectric thin films

Ferroelectric Na0.5La0.5Bi4Ti4O15 (NaLaBTi) thin films were prepared by a chemical solution deposition method. The NaLaBTi thin films annealed at 750 °C under oxygen atmosphere were randomly oriented polycrystalline. Electrical properties of the NaLaBTi thin films were compared to Na0.5Bi4.5Ti4O15 thin films and better properties were observed in the NaLaBTi thin films. Remnant polarization (2Pr) and coercive electric field (2Ec) were 43 µC/cm2 and 204 kV/cm at an applied electric field of 478 kV/cm, respectively. Leakage current density was 1.95 × 10− 6 A/cm2 at 100 kV/cm. Dielectric constant and dielectric loss were 805 and 0.05 at 1 kHz, respectively. Switchable polarization was suppressed by 15% after 1.44 × 1010 switching cycles.