Cobalt ferrite films were prepared by spray pyrolysis with post-annealing. For the as-
deposited film, the differential scanning calorimetry measurement shows a crystallization
peak at around 375° C during the isochronal heating at 20° C/min, and the X-ray diffraction
pattern shows its amorphous-like characteristic. The isothermal post-annealings were
performed for 2 h at various temperatures from 400 to 700° C, leading to the crystallization of
films, forming the spinel structure. The cross-sectional analysis with scanning electron …