Preparation of barium titanate and related materials by the alkoxide-hydroxide route

Formation of perovskites MTiO 3 (M = Ba, Sr) at low temperature (<100° C) by heterogeneous reactions of M(OH) 2 aqueous solutions with hydrolysis products of Ti(OBu) 4 is discussed. Reaction products are characterized by means of chemical and X-ray analysis, and electron microscopy. Reaction rate is enhanced by hydroxide concentration and reaction temperature, and increases drastically when Sr(OH) 2 is used instead of Ba(OH) 2 . Particles shape and size of the perovskites formed is independent of morphology of Ti(OBu) 4 hydrolysis product. The main factor of perovskites morphology regulation lies in the rate of M(OH) 2 absorption. Lowering the absorption rate allows us to prepare uniform perovskite powders which can be readily sintered to ceramic bodies with high dielectric permittivity.