Investigation on the amorphous-crystalline transition and microstructure of sol-gel derived (Ba1-xSrx)TiO3 thin films

(Ba1-xSrx)TiO3 (BST) ferroelectric thin films were fabricated by sol-gel pr ocessing, using Ba(Ac)(2), Sr(Ac)(2), and Ti(OC4H9)(4) as starting material s. Differential scanning calorimetry (DSC), backscattering scanning electro nic microscopy (BS-SEM), and X-ray diffraction (XRD) were employed to inves tigate the effect of chelating agents on the phase formation characteristic s and microstructure of the BST films. It was found that the chelating agen ts, acetate acid (HAc) and acetylacetone (HAcAc), changed the crystallizati on path from amorphous to crystalline phase during annealing. BS-SEM reveal ed that HAcAc improved the densification and compositional homogeneity in t he microregion of the films. These phenomena were explained by the modified condensation property of the precursors. (C) 2000 Elsevier Science Ltd. Al l rights reserved.