Narrow Results

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.