High-Resolution Transmission Electron Microscopy Studies of Sol-Gel-Derived Cobalt-Substituted Barium Ferrite

Nanocrystal specimen of cobalt (II)-doped magnetoplumbite (M-type) BaFe₁₂O₁₉ were synthesized via a sol-gel method using ethylene glycol as precursor. Hexagonal-like platelets and other morphologies of ferrites were obtained at the final stage of annealing process. The specimens were characterized using X-ray diffraction, SQUID magnetometry measurement and high-resolution transmission electron microscopy. The saturation magnetization of the specimen at 300 K was found to be greatly reduced from 48 (3) emu/g in parent ferrite to 28 (3) emu/g in the doped ferrite. A total reduction of 74% in the value of intrinsic coercivity was recorded, 276 (15) G from the doped ferrite compared to 1080 (54) G in the parent ferrite.