Formation and properties of SrBi2Ta2O9 thin films

Layered structure SrBi2Ta2O9 thin films were grown on Pt/Ti/Si/SiO2 substrates by laser ablation. The films were deposited at temperatures ranging from 500 to 750 degrees C and characterized for their phase formation, morphology, surface composition, and ferroelectric properties. Although crystalline phase formation was observed at temperatures as low as 500 degrees C, well defined saturated hysteresis loops were observed only in films deposited at temperatures of 700 degrees C or above. The transition in ferroelectric properties between 650 and 700 degrees C was associated with a change in orientation and grain size. The orientation of the films changed from highly c-axis oriented at 650 degrees C to randomly polycrystalline at 700 degrees C, while the grain size of the Films increased from an average value of 80 nm (at 650 degrees C) to 160 nm (at 700 degrees C). An understanding of process-structure relationships is required in order to fabricate high quality films at lower temperatures.