摘要
Chemical solution route was used to synthesize Bi3.1La0.9Ti3O12 and CoFe2O4. Alternate CoFe2O4/Bi3.1La0.9Ti3O12 layers were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. X-ray diffraction and SEM (scanning electron microscopy) studies show composite-like polycrystalline films. Films were studied for leakage current, dielectric response, ferroelectric and ferromagnetic properties. Leakage current was low (〈 10^-8 A) in electric field below 120 kV/cm, and the dielectric response shows relaxation. Dielectric loss (tan 8) reduces 〈 3% at 10^6 Hz. Two and four layer structures showed room temperature FE (ferroelectric) and FM (ferromagnetic) responses with FE Pr (polarization) 〉 25℃/cm2 and ferromagnetic Mr (memory) 〉 52 emu/cm3. Co-existence of FE and FM can be attributed to stress due to different crystal structures of the material involved in composite film structure.