Preparation of barium strontium titanate thin films by sol-gel technique

BST thin films were synthesized by using barium acetate, strontium acetate and titanium tetra n-butoxide as starting materials. Isopropyl alcohol and water were selected as solvents. Glacial acetic acid was used as catalyst. The BST thin films were prepared on the Al₂O₃ substrates by the sol-gel method. The crystallization behavior and structure characterization were studied by DTA, FTIR, XRD and SEM. Ba_0.5Sr_0.5TiO ₃ was derived through layer-by-layer heat treatment. The results indicate that it can effectively avoid producing cracks by adding dry chemical control additive, layer-by-layer sintering method, decreasing heating rate and prolonging heat treatment time. The result of XRD demonstrates that Ba _0.5Sr_0.5TiO₃ thin films appear perovskite phase. The SEM patterns show the thin films with good crystalline, high density and free of cracks.