Effects of substitution of Ti for Fe in BiFeO3 films prepared by sol-gel process

Ti substituted BiFe1−xTixO3+δ films have been prepared on indium-tin oxide (ITO)/glass substrates by the sol-gel process. The films with x=0.00-0.20 were prepared at an annealing temperature of 600 °C. X-ray diffraction patterns indicate that all films adopt R3m structure and the films with x=0 and 0.10 show pure perovskite phase. Cross-section scanning shows the thickness of the films is about 300 nm. Through 0.05 Ti substitution, the 2Pr increases to 8.30 μC/cm2 from 2.12 μC/cm2 of the un-substituted BiFeO3 film and show enhanced ferroelectricity at room temperature. The 2Pr values are 2.63 and 0.44 μC/cm2 for the films with x=0.01 and 0.2, respectively. Moreover, the films with x=0.05 and 0.10 show enhanced dielectric property since the permittivity increases near 150 at the same measuring frequency. Through the substitution of Ti, the leakage conduction is reduced for the films with x=0.05-0.20.