Growth behavior and thermally stable electrical properties of TiNbO₅ nanosheet thin films grown using the electrophoretic method

TiNbO₅ (TNO) thin films were deposited by electrophoresis at room temperature by using TNO⁻ nanosheets. These TNO films exhibited a large (001) interplanar distance (1.18 nm) owing to the presence of TBA⁺ between the TNO layers. The TBA⁺, which were used to synthesize the TNO⁻ nanosheets, were removed from the TNO film after annealing at 600 °C. Two types of structures were developed in the film annealed at 600 °C: type-1 and type-2, which revealed (001) interplanar distances of 0.52 and 0.71 nm, respectively. The TNO film annealed at 600 °C showed a dielectric constant of 48.5, low dielectric loss (0.02), and small leakage current density of 4.16 × 10⁻⁷ A/cm² at 0.6 MV/cm. The dielectric properties were stable with respect to the film thickness and the applied electric field; the dielectric and insulation properties were maintained up to 300 °C. Therefore, TNO films are good candidates for high-temperature capacitors.