等量La-Zn替代对锶铁氧体结构和磁性能的影响

Effect of La-Zn substitution on the microstructure and magnetic properties of Sr-ferrite

采用陶瓷工艺制备了La、Zn替代的Srl-xLaxFel2-xZnxO19(x=0,0.05,0.1,0.15,0.2,0.25)锶铁氧体,分析了La3+,Zn2+共同取代对锶铁氧体结构和磁性能的影响。X射线衍射分析表明,随着La3+、Zn2+离子替代量的增加,锶铁氧体主体仍为六角晶结构。通过扫描电镜对样品的形貌结构进行分析,测试结果显示铁氧体晶粒主要呈六角锶铁氧体结构;随着La3+、Zn2+取代量的增加,晶粒变得细小。磁性能测量显示,样品的Br随掺杂量的增加先增大后减小,当取代量x=0.15时,Br达到最大值。Hcb和Hcj则随着La3+、Zn2+掺杂量的增加迅速减小。这说明添加适量的La3+、Zn2+可以有效地提高材料的剩磁,但对永磁体的矫顽力有不利影响。

Strontium ferrites with La and Zn ions substitution（Sr1-xLaxFe12-xZnxO19 （x=0, 0.05, 0.1, 0.15, 0.2, 0.25））were prepared by conventional ceramic method, and the influence of Co-doped La3＋, Zn2＋ ions on the microstructure and magnetic properties of hexagonal strontium ferrites has been investigated. X-ray diffraction analysis showed that, with increasing La3＋, Zn2＋ ion substitution, strontium ferrite remains hexagonal strontium ferrite structure. SEM results showed that the sample has grain shape of hexagonal ferrite. The grain size decreases with increasing x. Measurement of magnetic properties indicated that, residual magnetic induction Br increases first and then decreases with increasing x, and the maximun value was obtained when the substitution amount x is 0.15. Coercive force Hcj and Hcb decrease quickly with the increase of La3＋, Zn2＋ dopants. It demonstrated that proper substation of La3＋, Zn2＋ is fruitful to residual magnetization but harmful to coercivity of the ferrite.