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Barium strontium titanate (BST) was produced in a teflon lined pressure vessel using a high temperature hydrothermal technique and controlling the processing parameters of Ba+Sr concentration, Ba and Sr ratio, temperature, reaction period and TiO₂ concentration. It was found that this technique produces BST powders of less than 200 nm particle size with high degree of crystallinity. However, most BST powders tend to be strontium rich. Thus, excess barium in the initial solution was essential in order to produce a high barium content in the final product, which was important to obtain good electrical properties. A high TiO₂ concentration was also crucial in producing BST with a high Ba content, though this parameter was responsible for a multiphase structure. The period of hydrothermal reaction was important for stoichiometric reaction.

This effort aimed to investigate the differences between raw materials and thin films to enhance the film performance and get encouraging results. Barium strontium titanate (BST) is a solid solution consisting of titanate barium (BT) and titanate strontium (ST). BST powder was synthesized using the sol–gel process, and BST film was deposited using pulsed laser deposition (PLD). Barium, strontium acetate, and Ti-isopropoxide were utilized as raw material sources. XRD was used to characterize the BST perovskite crystal structure. The SEM and LCR meters revealed morphology surface and dielectric properties. XRD pattern shows a cubic structure phase. The particle size of the bulk exhibited 122.88nm while the film particle size was 84nm. The dielectric constant of the bulk shape exhibited was greater than the form of the films, which was attributed to different thicknesses, densities, defects, and porosity.