Preparation of ferroelectric BaNb₂O₆ by the urea method

A precipitate was formed when an aqueous solution of BaCl₂, NbF₅ and urea in required ratio (the ratio of total metal cations to the urea is five) is heated on a water bath at 100 °C. This precipitate on decomposition at 600 °C yielded the nanocrystallites of BaNb ₂O₆ (BN), as confirmed by X-ray diffraction study (XRD). This is a much lower temperature as compared to that prepared by traditional solid state method (1000° C) as reported for the formation of BaNb ₂O₆. Transmission electron microscope (TEM) investigations revealed that the average particle size is 85 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found to be 900. The ferroelectric hysteresis loop parameters of these samples were also studied.