Barium strontium titanate (Ba0.7Sr0.3TiO3) ferroelectric films produced by electrophoretic deposition

Ba0.7Sr0.3TiO3 films with controlled thickness of above 20 μm were produced on metal substrates by an electrophoretic deposition method (EPD). The composition, crystal structure and microstructure of the deposited films were characterised using scanning electron microscopy and X-ray diffractometry. The dielectric properties were measured with a Hewlett-Packard 4294A precision impedance analyser. The sintered BST films showed a sharp perovskite structure with uniform microstructure. The results indicated that a typical BST film of 20 μm thick produced by EPD after sintering for different times exhibited a relative dielectric constant ranging from 2300 to 5200 at room temperature and a dissipation factor ranging from 0.062 to 0.118 at 1 kHz. These films also possess excellent adhesion to the substrate after the sintering treatment.