Structure and ferro/piezoelectric properties of SrBi4Ti4O15 films deposited on TiO2 buffer layer

TiO2 buffer layer was introduced between SrBi4Ti4O15 (SBTi) thin films and Pt bottom electrodes through the soft chemical solution. The obtained films were characterized by X-ray diffraction, atomic force microscopy and electrical properties. Unlike thin film crystallized directly onto a highly (1 1 1)-oriented Pt bottom electrode, the thin film on TiO2 buffer layer was a single phase perovskite with random orientation. The dielectric and ferroelectric properties of the SBTi/TiO2 thin films deposited on Pt coated Si substrates are evaluated, leading to the potential of the TiO2 buffer layer for the integrated devices. Meanwhile, SBTi thin films deposited directly on (1 1 1) Pt bottom electrode reveal a weak ferroelectricity along c-axis direction.