High Coercivity of Co-Ferrite Thin Films Prepared by Sol–Gel Method

Magnetic properties related to nano-structure have been investigated for sol-gel grown spinel Co-ferrite thin films of which thickness was 200-300 nm controlled by spin coating. The magnetic properties depended on the annealing temperature, and the coercivity of 6.3kOe was obtained at 923 K, which is about three times higher than that ever reported in Co-ferrite thin films by sol-gel method. The microstructure transformed into columnar from granular at the annealing temperature of 923 K, where magnetic anisotropy and high squareness ratio was observed