Ferrimagnetic Cobalt Ferrite Films Prepared by the Sol-Gel Process

Abstract

ABSTRACTFerrimagnetic oxide films have been shown to have potential for use as Magneto-optical information storage Materials. Cobalt ferrite films are particularly interesting for magneto optical information storage due to their high magneto optical rotation [1]. In this work, synthesized soluble cobalt (II) and iron (III) Methoxyethoxides were mixed in stoichiometric ratios for use as Co and Fe precursors in the preparation of CoFe2O4ferrimagnetic films. The decomposition of the precursors was characterized by thermogravimetric analysis.CoFe2O4 films were prepared by the dip coating technique using fused silica substrates. These films were then heat treated at temperatures ranging from 200°C to 600°C to study the transformation from an amorphous film to a crystalline film as determined by x-ray diffraction. The Magnetic hysteresis behavior of the films as a function of heat treating temperature and hence crystallinity was also studied. As a general trend, films having a greater degree of crystallinity exhibited larger values of saturation magnetization and remanent Magnetization. The amorphous film was found to exhibit the highest coercive field, but low values of saturation and remanent Magnetization. The effect of heat treating under the influence of a magnetic field of 1.88 kÖe was found to enhance crystallization only slightly and had very little effect on the magnetic properties of the film.