Barium strontium titanate (BST, BaxSr1-xTiO3) powders were fabricated by reacting nanocrystalline TiO2 with aqueous alkaline solutions containing Ba and Sr at 80 degrees C. Measurements of reaction kinetics showed that Ba-rich BST compositions exhibited more rapid reaction rates compared with Sr-rich BST compositions, and the reaction rate increased monotonically with increasing Ba content. The average particle size also increased with increasing Ba content, with the particle growth rate of BaTiO3 being approximately a factor of 10 greater than SrTiO3. The increase in growth rate from Sr-rich to Ba-rich BST corresponded to a morphological transition from 20 to 30 nm cuboidal particles to 80 nm raspberry-like particles, respectively.