Development of nanograined hexagonal barium ferrite thin films by sol-gel technique

Nanograined hexagonal barium ferrite (BaFe₁₂O₁₉) thin films have been developed on naturally oxidized Si substrates by sol-gel technique using aqueous solution of metal chlorides. Coated films were heat treated at different temperatures ranging from 450 to 900°C, and all the films were characterized by using X-ray diffraction (XRD), inductive coupled plasma (ICP) spectroscopy, and field emission scanning electron microscopy (FESEM). The effects of temperature on the formation of BaFe₁₂O ₁₉ thin film were studied, and it was observed that hexagonal barium ferrite thin films with grain sizes of about 50 nm were formed above 700°C. Study on the magnetic properties of the films by vibrating sample magnetometer (VSM) showed that films exhibited large saturation magnetization and high coercivity in the range 247-355 emu/cm³ and 2.70-4.22 kOe, respectively, while the Curie temperatures (□_c) were in the range 443-457°C. The effects of temperatures on the magnetic properties were also studied.