Conduction behavior of SrBi2Ta2O9 thin film grown by pulsed laser deposition

SrBi2Ta2O9 (SBT) thin films with different Sr and Bi concentrations were prepared on Pt/Ti/SiO2/Si substrate by the pulsed laser deposition technique. The structural feature and surface morphology were characterized by X-ray diffraction and SEM studies. The ferroelectricity was confirmed by polarization-electric field (P-E) hysteresis loops. The measured value of remanent polarization (2P(r)) of Bi-excess SBT film was 14.3 muC/cm(2) with a coercive field (2E(c)) of 101 kV/cm at the applied voltage of 4 V. The dielectric constant and the ac conductivity of the Pt/SBT/Pt capacitor were investigated in the frequency range of 0.1 Hz-100 kHz and the temperature range of 25degreesC-400degreesC. From the slope of ac conductivity vs. 1/T plot, the activation energy was calculated to be 0.86 eV at the lowest frequency and high temperature range. Also electrical properties were investigated by current-voltage (I-V) measurements as a function of applied electric fields. To determine the influence of Sr and Bi concentrations on the SBT/Pt junction, the ferroelectric properties and conduction behavior of SBT thin films are discussed.