Randomly oriented Bi4Ti3O12 thin films derived from a hybrid sol-gel process

Randomly oriented ferroelectric Bi4Ti3O12 thin films have been prepared by a hybrid sol-gel process. Crack-free and crystalline films of similar to1 mum thickness have been deposited on Pt/Ti/SiO2/Si substrates. X-Ray diffraction (XRD) results show that predominant phase of Bi4Ti3O12 can be obtained at 550 degreesC, and the films are randomly orientated up to 700 degreesC. The film annealed at 700 degreesC, was measured to have a dielectric constant of 105, dielectric loss of 0.04, remnant polarization of 13.5 muC/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. (C) 2000 Elsevier Science B.V. All rights reserved.