Hydrothermal growth of highly textured BaTiO3 films composed of nanowires

Abstract

Textured barium titanate (BaTiO3) films are attracting immense research interest due to their lead-free composition and excellent piezoelectric and dielectric properties. Most synthesis methods for these films require a high temperature, leading to the formation of a secondary phase and an overall decrease in the electrical properties of the ceramic. In order to alleviate these issues, a novel fabrication method is introduced by transferring oriented rutile TiO2 nanowires to a textured BaTiO3 film at temperatures below 160 °C. The microstructure and thickness of the fabricated BaTiO3 films were characterized by scanning electron microscopy, and the crystal structure and degree of orientation were evaluated by x-ray diffraction patterns using the Lotgering method. It is shown that the thickness of the BaTiO3 film can be controlled by the length of TiO2 nanowire array template, and the degree of orientation of the textured BaTiO3 films is highly dependent on the film thickness; the crystallographic orientation has been measured to reach up to 87%. The relative dielectric constant (εr = 1300) and ferroelectric properties (Pr = 2.7 μC cm−2, Ec = 4.0 kV mm−1) of the textured BaTiO3 films were also characterized to demonstrate their potential application in sensors, random access memory, and micro-electromechanical systems.