Parametric optimization of a sol-gel process for the synthesis of highly-oriented (Pb, Ba)TiO₃ thin films

A sol-gel process incorporating lead acetate trihydrate, barium acetate and titanium isopropoxide as precursors, acetylacetone as a chelating agent, and ethylene glycol as a solvent was used to prepare solid solution (Pb_0.5,Ba_0.5)TiO₃. Water content, annealing temperature and heating rate were varied and the resulting effects on material properties were studied using TGA/DSC, FTIR, FESEM and X-ray diffraction. Crystallization of the perovskite structure occurred at a temperature as low as 450°C. Thin films were prepared by spin coating on (100) MgO using the optimized precursor sol. Pyrolysis and anneal temperatures were varied and the resultant film properties investigated. The pyrolysis temperature used to dry the film was found to strongly affect orientation. Under optimized conditions, highly oriented films were obtained at a crystallization temperature of 600°C.