Microstructure and Properties of a (Bi0.95Na0.75K0.15Li0.05)0.5Ba0.05TiO3 Ceramic Thick Film Prepared by Electrophoretic Deposition

Abstract

The changes in the microstructure and properties of a (Bi0.95Na0.75k0.15Li0.05)0.5Ba0.05TiO3 (BNKLT–BT) ceramic film were investigated when the ceramic film was deposited with the addition of platelike SrTiO3 (STO) via an electrophoretic deposition method. The platelike SrTiO3 (STO) was used as a template for inducing grain growth with a preferential orientation of [001], and as a protective plate for restraining some elements in the film from evaporating under heat treatment. The SrTiO3 templates were found to be an effective protective layer for restraining the evaporation of volatile elements when the templates are placed on the ceramic thick film. The STO/BNKLT–BT/STO/AgPd/Al2O3 samples were fabricated and heated at 1170 °C for 12 h. They showed a [001]-oriented texture structure and better ferroelectric properties. The textured microstructure could be observed with the occurrence of grain growth around the templates. When the maximum E (Emax) was 150 kV/cm, the textured film showed a remanent polarization (Pr) of 9 µC/cm2, which was larger than that of the nontextured film. The piezoelectric strain constant (d33*) derived from the slope of the strain curve was 62 pm/V for the textured film, which was 1.5 times that of the nontextured film.