La掺杂纳米晶Ni-Zn铁氧体的制备及电磁性能

采用高分子凝胶法制备了Ni0.5Zn0.5LaxFe2-xO4（x=0,0.02,0.05和0.08）纳米晶铁氧体.采用X射线衍射仪（XRD）、透射电镜（TEM）和HP8510网络分析仪分别对其结构、形貌和电磁性能进行了研究.结果表明,当x=0,0.02和0.05时,所得粉体为纯立方晶系尖晶石结构.Ni0.5Zn0.5Fe2O4粉体平均粒径为70nm.随着La离子掺杂量的增加,红外光谱中550cm-1处吸收峰向高波数移动,420cm-1处吸收峰向低波数移动.La离子的掺杂对Ni-Zn铁氧体的电磁性能有一定的影响.在X波段,与Ni0.5Zn0.5Fe2O4铁氧体相比,掺杂La的Ni-Zn铁氧体的tanδm值降低,tanδε值升高.Ni0.5Zn0.5La0.02Fe1.98O4铁氧体的tanδε平均值为0.616.

Synthesis and Electromagnetic Properties of Nanocrystalline Ni-Zn Ferrites Doped with Lanthanum

Nanocrystalline Ni0.5Zn0.5LaxFe2-xO4 ferrites with x =0, 0.02, 0.05 and 0.08 were successfully prepared by the polyacrylamide gel method. The structural characteristics, morphology and electromagnetic properties of the composite powders were obtained by X-ray diffraction (XRD), transmission electron microscope (TEM) and HP8510 network analyzer. The results show that the obtained Ni0.5Zn0.5-LaxFe2-xO4 ferrites with x=0, 0.02 and 0.05 are single phase cubic spinel structures. The average particle size of Ni0.5Zn0.5Fe2O4 ferrite is about 70 nm. The absorption band at around 550 cm-1 slightly shifts toward higher value and 420 cm-1 slightly shifts toward lower value with La-doped content increasing. La3+ ion doping had an intimate effect on the electromagnetic properties of Ni0.5Zn0.5LaxFe2-xO4 ferrites. The tan δm values of the none doped Ni-Zn ferrite are higher than those of the La-doped samples in the X band. The tan δε values of the La-doped Ni-Zn ferrites are higher than those of the none La-doped Ni-Zn ferrite. The average tan δε value for the specimen of x=0.02 is 0.616.