Dielectric Properties of Nanostructured Bi4Ti3O12 and Bi12TiO20 Films Prepared by Sol-Gel Method

In this paper, bismuth titanate (Bi4Ti3O12, Bi12TiO20) nanostructured films were successfully fabricated via sol-gel method. The structure and dielectric properties of the prepared thin films as a function of annealing temperature and applied frequency were investigated. In this order, two different solutions with optimal ratio of raw materials were prepared. The solutions were deposited on the substrates by dip coating, and then heat treated at different temperatures ranging from 300 to 700 oC for 1 h. The prepared films were characterized by means of Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and LCR meter. It was found that the single phases were formed when Bi4Ti3O12 and Bi12TiO20 samples were annealed at 600 oC, therefore, optimal condition could be obtained at this temperature. Dielectric studies showed that the dielectric constant and loss factor were increased with increased annealing temperatures. Also, the values of dielectric constant were decreased and dielectric loss increased with increasing frequency.