Low-temperature synthesis of SrBi2Ta2O9 ferroelectric thin films through the complex alkoxide method:: Effects of functional group, hydrolysis and water vapor treatment

SrBi2Ta2O9 (SBT) ferroelectric thin films were synthesized at lower temperatures by the sol-gel method using complex alkoxides. The effects of the complex alkoxide functional group, the amount of water used in hydrolysis, and a mixture of water vapor and oxygen flow during calcination, on the crystallization, the microstructural development, and the ferroelectric properties of the SET thin films were addressed. The film which was deposited from complex alkoxide solutions and then calcined at 250 degrees C in the mixture, contained a relatively smaller amount of the remaining alkoxy groups; and therefore, crystallized to SET via rapid thermal annealing at temperatures below 500 degrees C in an oxygen Bow. Crystallinity improved significantly and the microstructure was able to develop up to 650 degrees C. Remarkable grain growth was observed particularly in the SET thin film deposited from the ethanolic solution of the complex ethoxide. Film annealed at 650 degrees C exhibited the saturated P-E hysteresis loop and improved endurance behavior.