Magnetic Properties of Nanocrystalline Barium Hexaferrite Thin Films Prepared by Sol-Gel Method

Single-phase nanocrystalline BaFe₁₂O₁₉ thin films have been prepared on Si (110) substrates by sol-gel method. The efforts have been done to reduce the crystallite size of the single-phase barium hexaferrite thin films in order to develop the thin films for high-density magnetic recording media. Precursor solutions were primed with various Fe/Ba ratios and two kinds of basic agents. Then the coated films were heat treated at different temperatures. The effects of calcination temperature, molar ratio of Fe/Ba, and basic agent on phase composition, crystallites size, morphology, and magnetic properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and vibrating sample magnetometery (VSM) techniques. The results showed that the lowest calcination temperature for production of the single-phase barium hexaferrite thin film by sol-gel method was 700degC. This product exhibited a nanostructure with high in-plane coercivity.