Spray Pyrolysis of Fe3O4-BaTiO3 Composite Particles

Fe3O4-BaTiO3 composite particles were successfully prepared by ultrasonic spray pyrolysis. A mixture of iron(III) nitrate, barium acetate and titanium tetrachloride aqueous solution were atomized into the mist, and the mist was dried and pyrolyzed in N-2 (90%) and H-2 (10%) atmosphere. Fe3O4-BaTiO3 composite particle was obtained between 900 degrees and 950 degrees C while the coexistence of FeO was detected at 1000 degrees C. Transmission electron microscope observation revealed that the composite particle is consisted of nanocrystalline having primary particle size of 35 nm. Lattice parameter of the Fe3O4-BaTiO3 nanocomposite particle was 0.8404 nm that is larger than that of pure Fe3O4. Coercivity of the nanocomposite particle (390 Oe) was much larger than that of pure Fe3O4 (140 Oe). These results suggest that slight diffusion of Ba into Fe3O4 occurred.