Jahn-Teller Effect of Cu-Ferrite Films by Solid Reaction

Copper iron oxide (CuFe 2 O 4 :Cu-ferrite) thin film was prepared on a glass substrate by vacuum evaporation and solid reaction, and annealed at 400 °C in the air. The obtained film was identified by X-ray diffraction analysis as Cu-ferrite film having a tetragonal lattice. The axial ratio (c/a) of the film was 1.507 and was larger than that of ASTM data because the lattice distortion of the films seems to be large by difference of a preparation method. The temperature dependence of the magnetization and conductivities of the film showed remarkable changes at about 360°C, which were considered to be caused by phase transition due to the Jahn-Teller effect.