Ferroelectric polaron in layered perovskite ferroelectric thin films

High quality SrBi2 Ta2O9 ( SBT) ferroelectric thin films were fabricated on platinized silicon substrate by PLD. Electronic transport properties of SrBi2Ta2O9 ferroelectric thin films in temperature range of 10 to 300K were studied. The conduction mechanisms in the thin films were analyzed. The results indicate the existence of two conduction mechanisms in SBT ferroelectric thin films. Due to the SBT layered structure, the carrier transport can be divided into two parts: internal transport, which is between the (Bi2O2)(2+) layers, and external transport, which is across the (Bi2O2)(2+) layers. Especially, behavior of electric transport of the polaron as an internal transport carrier is first observed in the SrBi2Ta2O9 ferroelectric thin films. Activation energy of the internal transport carriers is E-a similar to 0.0556 eV. The results can be helpful in understanding the low DC leakage in SBT films at room temperature.