掺杂对包钴包亚铁磁粉中钴离子扩散行为的影响

Influence of Different Dopants on the Co immigration Behavior in CoFe γ Fe 2O 3 Particles

探讨了不同掺杂离子对包钴包亚铁型磁粉（ＣｏＦｅ－γ－Ｆｅ２Ｏ３）在热处理过程中钴离子宏观扩散行为的影响，通过化学剥离分析的方法分析热处理后的磁粉表层钴离子的分布，结果得到掺杂离子对钴离子宏观扩散所起阻碍作用能力大小与其有效半径有关，它们的相对阻碍作用能力比较为：Ｚｎ２＋＞Ｍｎ２＋＞Ｍｎ４＋＞Ｌａ３＋＞Ｍｎ７＋，其临界剥离度分别为：Ｚｎ２＋５８％、Ｍｎ２＋５０％、Ｍｎ４＋２９％、Ｍｎ７＋１７％和Ｌａ３＋２９％。而且热处理温度越高，钴离子向内扩散越深，磁粉的矫顽力越大。另外不同掺杂离子对热处理后的亚铁含量有较大影响。

The influence of different dopants on the diffusion behavior of Co 2+ cation of CoFe γ Fe 2O 3 during annealing has been discussed.Attained samples are steeped and stripped in hydrochloric acid solution for a long time.The content of cobalt in the solution is measured. It shows that different dopants have different inhibition capability on Co 2+ immigration which is connected with their efficient cation radii.The sequence of different cations inhibition capability on cobalt ion immigration is:Zn 2+ >Mn 2+ >Mn 4+ >La 3+ >Mn 7+ .And the cri tical stripping values of cobalt ion are as follows:Zn 2+ 58%,Mn 2+ 50%,Mn 4+ 29%,Mn 7+ 17% and La 3+ 29%.The higher an annealing temperature is,the deeper Co 2+ cation expands and the higher coercivity it gets.In addition,it is found that the different dopants have different effects on the content of Fe 2+ in final particles,and their mechanism have been suggested.