Preparation of Ferroelectric BaTiO3 Films by Electrophoretic Deposition Technique

Abstract

Barium titanate ferroelectric films on Pt substrates were fabricated by electrophoretic deposition (EPD) technique. The barium titanate films sintered at different temperature (600°C, 900°C, 1050°C, 1150°C, 1200°C) for 2h, which were prepared via repeated EPD-sintering route 2~3 times were sufficiently dense and had uniform microstructure. The XRD pattern and SEM microphotography have been measured in order to investigate the effects of the final annealing temperature on the phase compositions and microstructure of the film. The experiment results showed that barium titanate films were crystallized into the tetragonal phase at 1050°C and above. The room temperature dielectric constant (ε) and loss tangent (tanδ) at 1kHz were respectively determined for different samples sintered at 600°C, 900°C, 1050°C, 1150°C and 1200°C. Both ε and tanδ showed anomaly peaks at 125°C. The results showed that typical BaTiO3 films sintered at 1050°C having higher dielectric constant (ε=2300) and lower dielectric loss (tanδ=0.02). The room temperature remanant polarization (Pr) and coercive field (EC) were found to be 1.9μC/cm2 and 35kV/cm, respectively.