Investigation of sintered cobalt-zinc ferrite synthesized by coprecipitation at different temperatures: a relation between microstructure and hysteresis curves

The magnetic properties of sintered samples of cobalt-zinc ferrites produced from the corresponding coprecipitate were calculated based on hysteresis curves (Hc). The Hc values confirmed that soft ferrites were obtained by the procedure. A possible relation between the magnetic hysteresis curves and the microstructure of the sintered samples was investigated. The microstructure and the phases present in the sintered ceramic pieces, as well as those of their coprecipitated tri-metallic hydroxide precursor powders, were characterised by XRD, thermal analysis and SEM. It was found that sintering of Co0.5Zn0.5Fe2O4 at 1400 C led to 'honeycombing' of the ferrite grains. No single phase was present in the microstructure of a sample sintered at 1400 C. Thus, a more complete study was made of the behaviour of the microstructure at lower sintering temperatures, i.e., in the 1100-1350 C range. 23 refs.