Preparation and Properties of Bi_0.5Na_0.5TiO₃ Thin Films by Chemical Solution Deposition

Abstract

Bi_0.5Na_0.5TiO₃ (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 μm-thick BNT films annealed at 650°C exhibited ferroelevctric polarization hysteresis loops. With scanning probe microscopy, we measured the field-induced displacement of 0.6 μm-thick BNT film capacitors at −100°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 67 pm/V.

Acknowledgment

This work was supported by a research grant from IKETANI Science Foundation.