Frequency dependence of the dielectric properties and coercive field of SrBi2Ta2O9 thin films

Frequency dependence of dielectric constant and coercive field were investigated for SrBi₂Ta₂O₉ (SBT) capacitors. In our measured frequency range, the dielectric constant followed an universal-law dependence with various biases, which could be interpreted by constant phase model. The coercive field showed a power-low dependence for the frequency. However, the fitted exponent values did not agree well with the result or Ishibashi and Orihara theory. This suggested that the space charges also play an important role in the domain reverse.