Preparation of alkaline-earth titanates by accelerated solid-state reaction in water vapor atmosphere

Alkaline-earth titanates, MTiO3 (M = Mg, Ca, Sr and Ba), were prepared by solid-state reactions in air and water vapor atmospheres to investigate the effects of water vapor on the formation of MTiO3. The formation of MTiO3 was accelerated more or less by water vapor. Acceleration effect by water vapor increased in the following order: MgTiO3 and CaTiO3 ≪ SrTiO3 < BaTiO3. The formation of SrTiO3 and BaTiO3 was drastically accelerated by water vapor even though the coarse particles of SrCO3 and BaCO3 remained in the starting mixtures. The difference in its effect might be mainly attributed to the vapor pressure of M(OH)2. Gas-phase transport of M(OH)2 would become important for the formation of MTiO3 by solid-state reactions in water vapor atmosphere.