Sol-Gel Thin Films of BaFe12O19 from Chemically Modified Alkoxide Precursors

Homogeneous BaFe₁₂O₁₉ (BaM) thin films have been prepared by the dip-coating technique on microscope slides and SiO₂ wafers using barium and iron alkoxides as precursors, and diethanolamine as a modifier. In order to optimise the coating conditions, the influence of the alkoxide, water and modifier on the sol viscosity, thickness and appearance of the Fe₂O₃ films has been investigated. For comparison of the crystallisation and magnetic properties, powders of the same composition as the films have been also prepared by the sol-gel method. The BaM phase appears after annealing at 650°C for 6 hours. The BaM film and powder, heated at 850°C for 6 hours, give coercive force of about 3000 and 5500 Oe, respectively.