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

摘要

Nanograined hexagonal barium ferrite (BaFe_(12)O_(19)) 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 deg 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 BaFe_(12)O_(19) thin film were studied, and it was observed that hexagonal barium ferrite thin firms with grain sizes of about 50 nm were formed above 700 deg 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/cm~3 and 2.70-4.22 kOe, respectively, while the Curie temperatures (Tc) were in the range 443-457 deg C. The effects of temperatures on the magnetic properties were also studied.