Effect of ethylene glycol on the orientation and magnetic properties of barium ferrite thin films derived by chemical solution deposition

• Oriented barium ferrite films were fabricated on (0001) sapphire substrates.
• Glycol addition improved phase purity, orientation and magnetic anisotropy.
• XRD φ-scan confirms the existence of epitaxial hematite phase under some conditions.

M-type barium ferrite (BaM) film is a promising candidate for magnetic recording media and the next-generation high-frequency microwave material. BaM films were fabricated using a chemical solution spin-coating deposition method on (001) plane sapphire. The effect of ethylene glycol (EG) on precursor solution and annealing temperature on microstructure and magnetic properties were investigated. X-ray diffraction showed that strong out-of-plane (001) texture in BaM films can be achieved with adequate EG addition. Films fabricated without EG addition or annealed at lower temperatures showed partial hematite secondary phase. The epitaxial formation of hematite secondary phase on sapphire substrate was confirmed by the X-ray diffraction φ-scan technique. Magnetic measurements showed out-of-plane anisotropy in BaM films. The crystallographic texture and magnetic anisotropy of the films are related to the film microstructure.