Sol-gel derived BaTiO3 nanopowders

Pure tetragonal phase barim titanate nanograin with an average diameter of about 54 nm has been synthesized via a sol-gel route starting from soluble precursors of barium and titanium and without surfactant. The gel was peptized and crystallized in water under a refluxing condition. The effect of pH value on the properties of BaTiO3 powder was investigated. BaTiO3 samples were characterized by X-ray diffraction, Brunauer-Emmett-Teller analysis, transmission electron microscope and thermal gravimetric analysis. It was found that the pH value of solvent had a great influence on the calcination temperature of powders while BaTiO3 crystallites were formed at 800 degrees C by acidic catalyst process and at 1000 degrees C by using basic additives. Higher initial pH led to smaller crystallite sizes of BaTiO3 powders. As-prepared powder has perovskite tetragonal structure with an average grain size of 54 nm and a high BET value of 25 m(2)/g for pH 9. Sol-gel route has shown many distinctive advantages in the preparation of high-purity BaTiO3 nanopowders without Ba Ti losses and hazardous wastes. (C) 2008 Elsevier B.V. All rights reserved.