Structural and electrical characterization of chemical-solution-derived Bi₅FeTi₃O₁₅thin films

Abstract

Thin films of Fe-containing Aurivillius phase Bi5FeTi3O15 (BFTO) were prepared using the chemical solution deposition method. The structures of the films were analysed using x-ray diffraction and Raman spectroscopy. The surface topography and crystal microstructure were characterized by AFM and FESEM. The remanent polarization (2Pr) and coercive field (Ec) of BFTO thin films under an electric field of ∼570 kV cm−1 are determined to be 35.5 µC cm−2 and 171 kV cm−1, respectively. The normalized polarization of BFTO thin films under 285 kV cm−1 decreased to 66% after being subjected to 5.2 × 109 read/write cycles. A comparison between BFTO and SrBi4Ti4O15 in Raman spectra and ferroelectric behaviour is also presented. The leakage current density measurement reveals that the conduction mechanism of BFTO thin films in the intermediate electric field range from ∼50 to ∼200 kV cm−1 is dominated by Schottky emission. With an electric field higher than ∼200 kV cm−1, the leakage behaviour is mingled with different conduction mechanisms.