Study on the Ce substitution effects of BiFeO3 films prepared by a sol–gel process

Ce substituted Bi1−xCexFeO3 (BCFO) thin films are grown on Pt/Ti/SiO2/Si substrates by a sol–gel process. The films with x = 0.00 , 0.05 and 0.10 were prepared at an annealing temperature of 500 ∘C. The ferroelectric and dielectric properties of the Ce substituted films are compared with those of BiFeO3 (BFO) thin film. X-ray diffraction patterns indicate that all films adopt R 3 m structure and an impure phase was identified in the film with x = 0.10 . Cross section scanning shows that the thickness of the films is about 280 nm. Enhanced saturation at room temperature was observed by measuring the electric hysteresis loops. The film with x = 0.00 has the largest remanent polarization of 66.3 μC/cm2, under an applied field of 1050 kV/cm. The remnant polarizations are 50.2 μC/cm2 and 36.3 μC/cm2 for the films with x = 0.05 and 0.10 under the same applied fields, respectively. Moreover, all films show small dielectric dispersion and dielectric loss. By the substitution of Ce, the leakage current density is reduced.