共沉淀法合成Zn掺杂Co_2-Y平面六角铁氧体粉的热力学分析

Thermodynamic Analysis on Preparation of Zinc Doped Co_2-Y Planar Hexagonal Ferrite Powder by Chemical Co-precipitation Method

通过对Me(Ba2+,Zn2+,Co2+,Fe3+)-CO32--NH3-H2O体系进行热力学分析,得到不同的总碳浓度(cC)和总氮浓度(cN)时各金属离子总浓度(cMe)与pH值关系,由此确定4种金属离子共沉淀完全的pH值范围。热力学分析表明:以Na2CO3和NH3·H2O作沉淀剂,用共沉淀法合成Zn掺杂Co2-Y平面六角铁氧体粉时,体系pH值由Ba2+和Zn2+沉淀完全的酸度条件决定,而两者取决于cC和cN的相对关系;当cC>1.000mol·L-1、cN<0.100mol·L-1时,控制pH值在8～12范围内,即可确保共沉淀完全。

The pH-dependence of cMe under various total carbon concentration Cc and total nitrogen concentration cN in the Me-CO3^2--NH3H20 system were presented by thermodynamic analysis, and the co-precipitation window of Ba^2＋, Zn^2＋, Co^2＋ and Fe^3＋ was obtained at a suitable pH value. The results show that the co-precipitation window to prepare zinc doped Co2-Y planar hexagonal ferrite powder is mainly controlled by the pH value for completely precipitation of Ba^2＋ and Zn^2＋in co-precipitation process, and the precipitants are Na2CO3 and NH3·H2O, while the field of co-precipitation of Ba^2＋ and Zn^2＋ is determined by the reciprocal ship of cC and CN. In this system, when cc value is greater than 1.000 mol·L^-1, and cN value is smaller than 0.100 mol·L^-1, the four kinds of metal ions can be completely co-precipitated in pH value range from 8 to 12.