| The conditions for the formation of Mn-Zn ferrite by oxygen oxidation in aqueous suspension were investigated with various pH, temperature, and Mn/Zn molar ratio and were compared with those of Mn ferrite and Zn ferrite. The oxidation products were then examined by XRD, chemical analysis, electron microscopic observation and magnetic property measurements. The most favorable pH at 70℃ to form the Zn and Mn ferrite and 9.0 and 12.0 respectively. In Mn-Zn ferrite formation, the reaction temperature affected the amount of Zn incoporated into ferrite than that of Mn. When changing the Mn/Zn molar ratio, it is possible to control the chemical composition of Mn-Zn ferrite. At temp. 70℃, M/Fe molar ratio 0.5, Mn/Zn molar ratio 1.5 and pH 11, Mn-Zn ferrite is obtained that has nearly stoichiometrical composition Mn_(0.45)Zn_(0.51)Fe_(2.04)O₄ and its saturation magnetization was 38 emu/g. |
|
