Randomly oriented Bi 4Ti 3O 12 thin films derived from a hybrid sol–gel process

Abstract

Randomly oriented ferroelectric Bi 4Ti 3O 12 thin films have been prepared by a hybrid sol–gel process. Crack-free and crystalline films of ∼1 μm thickness have been deposited on Pt/Ti/SiO 2/Si substrates. X-Ray diffraction (XRD) results show that predominant phase of Bi 4Ti 3O 12 can be obtained at 550°C, and the films are randomly orientated up to 700°C. The film annealed at 700°C, was measured to have a dielectric constant of 105, dielectric loss of 0.04, remnant polarization of 13.5 μC/cm 2, and coercive field of 60 kV/cm. The random orientation mechanism and the effect of annealing temperature on the dielectric and ferroelectric properties of the films were qualitatively discussed.