Properties of ferroelectric SrBi 2Ta 2O 9–Bi 4Ti 3O 12 thin films derived by the sol–gel method

Abstract

Ferroelectric (1− x)SrBi 2Ta 2O 9– xBi 4Ti 3O 12 ( x = 0 – 0.4 ) thin films were fabricated by the sol–gel method. Multiple phases of SrBi 2Ta 2O 9–Bi 3TiTaO 9 solid solution, SrBi 2Ta 2O 9 and Bi 4Ti 3O 12 were formed and good electric properties were obtained in the films. With the increase in composition, x, the remnant polarization has no obvious change, but the coercive field increased. The 0.8SBT–0.2BIT films showed the lowest dielectric constant values, well-saturated hysteresis loops and lower leakage current densities. The parameters of the 0.8SBT–0.2BIT film annealed at 750 °C were 150 for dielectric constant, 13.5 μC/cm 2 for remanent polarization (2 P r), 152 kV/cm for coercive field (2 E c) and 5.88×10 −8 A/cm 2 (at 200 kV/cm) for leakage current density.