Polarization Properties of Bismuth Strontium Tantalate Ceramic Films Deposited by Aerosol Deposition Method

Abstract

We report aerosol deposition (AD) method for preparation of bismuth layer-structured ferroelectric thick films with enhanced ferroelectric and insulating properties. Constitution phase, crystal structure, polarization and leakage current properties of SrBi2Ta2O9 (SBTa) thick films with thickness of 2–4 µm were investigated. While obtained as-deposited SBTa films have slight c-axis grain orientation, the degree of orientation for the films annealed at higher than 1000 °C was the same as that for sintered bulks. Fracture cross-sectional scanning electron microscopy (SEM) images revealed that the as-deposited SBTa films on glass substrates had a fully dense microstructure. The low leakage current density (J) of less than 10-7 A/cm2 at 1 MV/cm was observed for SBTa films annealed at less than 900 °C, and the SBTa films annealed at 900 °C indicated a remanent polarization (Pr) of 5.7 µC/cm2, which is larger than that of sintered bulks (Pr of 4.7 µC/cm2) fabricated by conventional solid-state reaction using the same starting raw powder used for the AD method.