On-line version ISSN 1980-5373
TEIXEIRA, Ana Maria Rangel de Figueiredo; OGASAWARA, Tsuneharu and NOBREGA, Maria Cecília de Souza. Investigation of sintered cobalt-zinc ferrite synthesized by coprecipitation at different temperatures: a relation between microstructure and hysteresis curves. Mat. Res. [online]. 2006, vol.9, n.3, pp. 257-262. ISSN 1980-5373. http://dx.doi.org/10.1590/S1516-14392006000300003.
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. X ray diffraction, thermal analysis and scanning electron microscopy were used to characterize the microstructure and the phases present in the sintered ceramic pieces, as well as those of their coprecipitated tri-metallic hydroxide precursor powders. It was found that sintering of Co0.5Zn0.5Fe2O4 at 1400 °C led to "honeycombing" of the ferrite grains and that there was no single phase in the microstructure of a sample sintered at 1400 °C. Thus, a more complete study was made of the behavior of the microstructure at lower sintering temperatures, i.e., in the 1100-1350 °C range.
Keywords : cobalt-zinc ferrite; hysteresis curve; coprecipitation.