Focus on the ferroelectric polarization behavior of four-layered Aurivillius multiferroic thin film

The well-saturated ferroelectric hysteresis loops with double remnant polarization up to 50?μC/cm² were obtained in four layered Aurivillius-type multiferroic Bi₅FeTi₃O₁₅ thin film. Pulsed positive-up negative-down polarization measurements demonstrate the intrinsic ferroelectric polarization, which present optimal rectangularity and polarization value. The hysteresis loops measurements with larger frequency range of 0.2–100?kHz indicate stable and ultra-fast switching speed of ferroelectric domains. Persistent retention properties were observed, and they are also independent of the applied electric field. In fatigue test an increased dielectric constant is observed along with the suppression of switchable polarization. Both of them can be restored partly to their original values via the stimulating of high electric field. The block domain switching due to the oxygen vacancies aggregated on domain walls are discussed for those characteristics. It is providing important contributions of domain wall pinning in the polarization degradation of Aurivillius-type ferroelectric films with four layers.