Multiferroic Double-layer BiFeO3-CoFe2O4 Composite Films Prepared by Pulsed-Laser Deposition

Multiferroic BiFeO3-CoFe2O4 (BFO-CFO) double-layer thin film has been deposited on platinized silicon substrate by pulsed-laser deposition. The BFO and CFO thin layers are deposited at 450 and 600 °C respectively. The diffraction peaks from spinel CoFe2O4 phases can be observed from the x-ray diffraction patterns of the double-layer BFO-CFO films. Dielectric constant and loss of the BFO-CFO films are of around 60 and 0.06 respectively, changing little with increasing the frequency. The leakege current density is about 10^-6 A/cm² under the field of 100 kV/cm. BFO-CFO thin films exhibit good ferromagnetic properties with the saturation magnetization of 120 emu/cm³.