Structural, Ferroelectric and Ferromagnetic Properties of Single-Phase Bi_0.95Ba_0.05FeO₃ Thin Film Prepared by Pulsed Laser Deposition

Single-phase Bi_0.95Ba_0.05FeO₃ (BBFO) thin film was grown on Si (111) substrate by a pulsed laser deposition method. The analysis of crystal structure identifies that the BBFO thin film has a rhombohedrally distorted perovskite structure with R3c space group. The morphologies investigated by high-resolution field emission transmission electron microscopy and atomic force microscopy reveal that the BBFO thin film is polycrystalline and consists of uniform grains with an average size of about 110 nm, of which surfaces are smooth. Ferroelectric property of the BBFO thin film was analyzed and the remnant polarization (P_r) is about 3.9 μC cm⁻². Magnetic measurements reveal that the BBFO thin film has a strong ferromagnetic behavior at room temperature with a 36.76 emu cm⁻³ saturated magnetization (M_s) and 2998 Oe coercivity. Furthermore, the original mechanisms of ferroelectric and ferromagnetic properties were discussed. This work is believed to contribute a novel multiferroic material, which should open a way toward the integration of multiferroic material and semiconductor material for future tunable multifunctional devices.