Enhanced in-plane ferroelectricity in BaTiO3 thin films fabricated by aqueous chemical solution deposition

摘要

Ferroelectric BaTiOsub3/sub is widely used in capacitors, but the low Curie temperature limits a further use of BaTiOsub3/sub. In this work we present an aqueous chemical solution deposition (CSD) route for BaTiOsub3/sub thin films, demonstrating that organic solvents are not required for CSD. Textured BaTiOsub3/sub thin films were deposited on SrTiOsub3/sub substrates. The in-plane dielectric properties were investigated using interdigitated electrodes and ferroelectric switching was observed up to 160±5 °C. The increased Curie temperature is proposed to result from thermal strain due to a mismatch in thermal expansion coefficient between the film and the substrate, and is in good agreement with the theory of strain engineering in BaTiOsub3/sub. Finally, the decomposition and crystallization of BaTiOsub3/sub during thermal treatment were determined by the combination of thermal analysis, IR spectroscopy and X-ray diffraction of powder prepared from the solution.