Hydrothermal synthesis of tetragonal BaTiO3 nanotube arrays with high dielectric performance.

Tetragonal Barium titanate (BaTiO3) nanotube arrays have been prepared using the template-assisted hydrothermal method combined with an annealing process. The in-situ chemical conversion of TiO2 nanotube array templates ensured that BaTiO3 maintained the morphology of the nanotube architectures. Moreover, X-ray diffraction and Raman spectrum characterization were used to confirm that the BaTiO3 nanotube arrays had a tetragonal phase after the use of a simple annealing technique. Typical hysteresis loops showed their ferroelectricity, with the remanent polarization and coercive fields being 2.57 microC/cm2 and 2.52 kV/cm, respectively. The relative dielectric constant of the tetragonal BaTiO3 nanotube arrays reached up to 1000 and the dielectric loss was as low as 0.02 at 1 kHz at room temperature.