α-axis Oriented Bi_4Ti_3O_12 Thin Films Deposited on Si(111) by Femtosecond Laser Ablation and Its Characteristic ofI-VCurve

The polycrystalline Bi4Ti3O12 thin films were successfully prepared by femtosecond laser deposition on Si(111) wafers. X-ray diffraction (XRD) showed that Bi4Ti3O12 thin film was highly c-axis-oriented deposited at room temperature (20℃), but the film was highlyα-axisoriented deposited at 500℃. The remanent polarization (Pr) and coercive force (Ec) ofα-axisoriented samples were measured to be 15μC/cm2 and 48kV/cm respectiovely. An equivalent circuit with distributed constants of Bi4Ti3O12/Si was introduced to interpret the relationship between theⅠ-Ⅴcharacteristic curve and the ferroelectric hysteresis loop of Bi4Ti3O12 deposited on Si.