Ferroelectric SrBi4Ti4O15 thin films with high polarization grown on an IrO2 layer

Ferroelectric strontium bismuth titanate (SrBi4Ti4O15) thin films with a high remanent polarization were produced by a chemical solution deposition method. Pt and IrO2 layers were used as substrates. It was found that ferroelectric SrBi4Ti4O15 films can be successfully fabricated on IrO2: They demonstrate a saturated hysteresis loop at 5 V with remanent polarization (Pr) of 19 μC/cm2 and coercive field (Ps) of 116 kV/cm. SrBi4Ti4O15 films grown on IrO2 show larger and denser grains and controlled surface morphology. The grains are random oriented, while those of films on Pt are mainly c-axis oriented. It is concluded that the high remanent polarization of the films grown on IrO2 originates from the relatively high concentration of a- and b-axis orientations.