Preparation and Properties of Bi0.5Na0.5TiO3 Thin Films by Chemical Solution Deposition

Bi0.5Na0.5TiO3 (BNT) films were fabricated by chemical solution deposition on Pt/TiO2/SiO2/Si substrates. Homogeneous and stable precursor solutions were prepared by controlling the reaction of starting metal alkoxides. By controlling the chemical composition and structure of the BNT precursor in solution and optimizing the heating conditions, we successfully synthesized perovskite BNT single-phase thin films with good surface morphology on Pt/TiO2/SiO2/Si substrates. The 0.6 m-thick BNT films annealed at 650 degrees C exhibited ferroelevctric polarization hysteresis loops. With scanning probe microscopy, we measured the field-induced displacement of 0.6 m-thick BNT film capacitors at -100 degrees C and at room temperature. Butterfly-shaped displacement strain loops were obtained in the BNT film capacitors, and the effective d33 value estimated from the slope of the loop was 67pm/V.