磁性纳米粒子MFe_2O_4的制备及其磁性能

Preparation of Nano-particle MFe_2O_4 and Its Magnetic Properties

为探究Fe_3O_4类磁性纳米粒子磁性能的优劣,采用水热合成法,将相同摩尔比例的Co、Nd、Ce、La和Ni掺杂到Fe_3O_4中,形成具有通式MFe_2O_4的磁性纳米粒子。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱(EDS)、动态激光散射粒径(DSL)和振动样品磁强(VSM)测试,分析了纳米粒子的结构、形貌、元素组成、粒径以及磁性能。结果表明,水热合成法可成功地将Co、Nd、Ce、La和Ni掺杂到Fe_3O_4主晶当中,形成圆形结构纳米粒子,粒子分散性好。其中,CoFe_2O_4的粒径最大,结晶能力最强,使得其具有较高的饱和磁化强度和极高的矫顽力,因此硬磁性能好。3组稀土(Nd、Ce和La)掺杂的纳米粒子中,NdFe_2O_4的粒径最小,同时较高的饱和磁化强度和极低的矫顽力使其具备优异的软磁材料性能。

To study the magnetic properties of Fe3O4 magnetic nanoparticles,we prepare the nanoparticles with the general formula of MFe2O4 by hydrothermal synthesis, doping the same mole ratio of Co, Nd, Ce, La and Ni into Fe3O4 The X-ray diffraction（XRD）, scanning electron microscope（SEM）,energy dispersive spectrometer（EDS）,dynamic light scattering（DSL） and vibrating sample magnetometer（VSM） measurements were carried out to analyze the structure, shape, element composition, size and magnetic properties of the nanoparticles. The results show that the hydrothermal synthesis successfully dopes Co, Nd,Ce, La and Ni into Fe3O4 crystal. The nanoparticles are almost round and well dispersed. The CoFe2O4 has the biggest particle size and strong crystallizability, thus it has the best hard-magnetic properties with high saturation magnetization and excellent coercivity. The NdFe2O4 has the smallest size among the three groups of nanoparticles doping with rare earth, and it owns excellent soft magnetic properties because of its high saturation magnetization and quite low coercivity.