Preparation of (Pb,Ba)TiO3 Powders and Highly Oriented Thin Films by a Sol-Gel Process

Solid solution Pb1-xBaxTiO3, with particular emphasis on Pb0.5Ba0.5TiO3, was preparedusing a sol-gel process incorporating lead acetate trihydrate, barium acetate, andtitanium isopropoxide as precursors, acetylacetone (2,4 pentanedione) as a chelatingagent, and ethylene glycol as a solvent. The synthesis procedure was optimized bysystematically varying acetylacetone: Ti and H2O:Ti molar ratios and calcinationtemperature. The resulting effects on sol and powder properties were studied usingthermogravimetric analysis/differential scanning calorimetry, Fourier transform infraredspectroscopy, Brunauer-Emmett-Teller analysis, and x-ray diffraction (XRD).Crystallization of the perovskite structure occurred at a temperature as low as 450 °C.Thin films were prepared by spin coating on (100) MgO. Pyrolysis temperature andheating rate were varied, and the resultant film properties investigated usingfield-emission scanning electron microscopy, atomic force microscopy, and XRD.Under optimized conditions, highly oriented films were obtained at a crystallizationtemperature of 600 °C