尖晶石结构MFe2O4(M=Ca,Mg,Cu,Zn)纳米晶粉末的制备和磁性能

摘要

Magnetic spinel-type MFe2O4 (M=Ca,Mg,Cu and Zn) nanocrystalline powders were successfully prepared by auto-combustion method using a novel amino-based gel.The phase identification,morphology and magnetic properties of as-synthesized powders were studied in detail.The high purity of synthesized MFe2O4 powders was comfirmed by energy dispersive X-ray spectroscopy.Magnetic properties of as-synthesized MFe2O4 nanocrystalline powders were investigated systematically.All the samples presented a rather narrow hysteresis loop,suggesting the soft magnetic features.The saturated magnetization (Ms) of the four ferrites were 2.1,29.3,24.1,and 4.2emu· g-1,respectively,and the residual magnetization (Mr) were 0.2,2.3,11.4,and 0.2 emu· g-1,respectively.M/Ms values of four ferrite samples were all less than 0.5.Zero-field-cooled and field-cooled magnetic properties of CaFe2O4 and MgFe2O4 samples as two typical ferrites were investigated in detail.The magnetization of CaFe2O4 sample presented an inconsistent variation tendency below 75 K due to the occurrence of magnetic phase transition.%采用新型氨基凝胶自燃法成功制备出尖晶石结构MFe2O4(M=Ca,Mg,Cu,Zn)纳米晶粉末.对合成粉体样品的物相、形貌和磁性能进行了详细的研究.经能量色散X射线谱分析确定了合成MFe2O4粉末的高纯度.系统地研究了所合成的MFe2O4纳米晶粉末的磁性能.所有样品的磁滞回线均较窄,表明了它们具有软磁的特征.经测试得出4种铁氧体的饱和磁化强度(Ms)分别为2.1,29.3,24.1和4.2 emu·g-1;剩余磁化强度(Mr)分别为0.2,2.3,11.4和0.2 emu·g-1.这4种铁氧体样品的M/Ms值均小于0.5.对CaFe2O4和MgFe2O4两种典型铁氧体的零场冷却和场冷磁性能作了详细的研究.其中CaFe2O4样品的磁化强度在75 K以下有不一致的变化趋势,这是由于其发生了磁相变.