Ferroelectric Bi1.1Fe0.9Co0.1O3 (BFCO) thin films were prepared on Pt/TiO2/SiO2/Si substrates by chemical solution deposition method using rapid thermal annealing (RTA). The thickness of all BFCO thin films is about 100 nm. Although the BFCO prepared at 545°C has a large value of difference of polarization at zero field, 88 C/cm2, the P-E hysteresis loop of the BFCO thin film prepared at 520°C looks like more saturated and shows 47 C/cm2 of difference of polarization at zero field in the applied electric field of 2 MV/cm. The leakage current of the BFCO film annealed at 520°C, is about 2 × 10-2 A/cm2 at room temperature (RT). Moreover, it is also shown that the saturated possibility of P-E hysteresis loops and in 2 MV/cm their apparent difference of polarization at zero field depend on not only the leakage current but also scanning frequency used to measure BFCO thin films. Accordingly, the P-E hysteresis loops of BFCO thin films prepared from 520°C to 545°C seem to be saturated at high frequency from 10 KHz to 20 KHz when these samples are measured at RT.
