| 摘要 |
PURPOSE:To prepare a sintered material having small particle diameters and improved uniformity of particle diameter and to provide improved high-frequency characteristics, by producing wet Mn-Zn ferrite powder into which calcium silicate obtained from silicic acid and calcium oxide is uniformly dispersed. CONSTITUTION:Aqueous solutions of ferrous nitrate, mangenese nitrate and zinc nitrate are prepared in a molar ratio of Fe2O3, MnO and ZnO of 10:4:1 and the mixed solution is added to an aqueous solution of calcium hydroxide at pH 9-10 while stirring. Mn-Zn ferrite is formed by an alkali reaction and uniformly dispersed into the aqueous solution. Then, an aqueous solution of Ca(OH)2 at pH slightly exceeding 10 and an aqueous solution, the pH is raised and exceeds 10 and Mn-Zn ferrite begins to precipitate. Simultaneously, sodium silicate is reacted with calcium hydroxide to form and precipitate calcium silicate and the calcium silicate is uniformly dispersed into the Mn-Zn ferrite. |
