Behaviour of cobalt ferrite in reducing atmosphere

Cobalt ferrite is one of the materials which have special properties that make it suitable for magnetic recording tapes manufacture. Cobalt ferrite is prepared by mixing chemically pure powders of Fe sub 2 O sub 3 and Co O in stoichiometric ratios then pressed at 30 kN into cylindrical form of compacts before being fired at 1473 K for 20 hrs. The characteristics of the prepared cobalt ferrite compacts have been studied using X-ray diffraction analysis technique, reflected light microscope and pore size analyser. The behaviour of cobalt wuestite phase (Co, Fe)O which was then subsequently reduced to (Co, Fe) solid solutions. The initial stages of reduction was found to be controlled by the combined effects of interfacial chemical reaction and gaseous diffusion mechanism whereas at the latter stages, the reduction was controlled mainly by interfacial chemical reaction mechanism. (author)