Effect of pH on the Preparation of Manganese Zinc Ferrite Powder by Alcoholic Dehydration of Citrate/formate Solution

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J. Korean Ceram. Soc. > Volume 32(10); 1995 > Article

Journal of the Korean Ceramic Society 1995;32(10): 1123.

알콜 탈수법에 의한 Mn-Zn Ferrite 분체 제조시 pH의 영향

김창범, 신효순, 이대희, 김창현, 이병교

경북대학교 무기재료공학과

Effect of pH on the Preparation of Manganese Zinc Ferrite Powder by Alcoholic Dehydration of Citrate/formate Solution

ABSTRACT

In the preparation of manganese zinc ferrite powders by alcoholic dehydration of citrate/formate solution. The effect of pH change on precipitation was investigated. The pH range for obtaining stable precipitates was studied. The glassy phase was obtained when the pH value of solution is higher than 5, and the formation mechanism of glassy phase was suggested. Below pH 5, the stable precipitates were formed, and the optimal pH was 2. Formation of glassy phase was accounted for the change of surface charge by pH change. The change of surface charge is caused by the interparticular agglomeration. The precipitate was redissolved into the water on the surface of precipitate itself and through the polymerization, it agglomerated. This mechanism is tought to be similar to that of viscous flow.

Key words: pH change, Glassy phase, Agglomeration, Viscous flow