【作者】 张月萍；

【导师】 宋平新；

【作者基本信息】 郑州大学 ， 凝聚态物理， 2013， 硕士

【摘要】 磁性纳米材料是集磁性材料与纳米材料于一体的功能材料,同时具有磁性材料的磁学性能和纳米材料特殊的物理化学性质,因此磁性纳米材料具有特殊的磁学性能,比如高矫顽力、超顺磁性、低的居里温度以及单磁畴等性质。近些年来,磁性纳米材料已成为研究热点。尖晶石型纳米铁氧体是一类重要的磁性纳米材料,具有很好的电磁性质,己广泛用于生物医学、磁储存材料、催化剂等领域。本文用溶胶凝胶法制备La3+掺杂Fe304纳米颗粒和CoFe2O4纳米颗粒。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和综合物性测量系统(PPMS)对制备好的样品的结构组成及物相、形貌尺寸和磁学性能进行了研究,分析讨论了制备过程中的参数对样品的影响,为下一步的工作提供实验依据。通过对研究分析得出：(1)La3+掺杂Fe304纳米颗粒的制备：自燃烧溶胶凝胶法缩短了样品的制备周期；研究了制备条件对La3+掺杂Fe304纳米颗粒的形貌的影响,得出用自燃烧溶胶凝胶制备的最佳参数为80℃恒温水浴5h、800℃焙烧5h等。(2) CoFe2O4纳米颗粒的制备：分别用PEG和PVA作为分散剂、凝胶剂制备了颗粒大小均匀的CoFe2O4纳米颗粒；用PEG和PVA制备的纳米颗粒的尺寸分别为20～40nm和～100nm；用PEG制备的CoFe2O4纳米颗粒的剩磁比和饱和磁化强度分别为0.42和143.11emu/g,分析其原因主要是C02+在A位和B位的重新分布；用不同量的PEG时,比较得出：PEG的最佳用量为4g。更多还原

【Abstract】 Magnetic nanomaterials are function materials which are concentration of magnetic materials and nanomaterials, having both magnetic properties of magnetic materials and special chemical and physical properties of nanomaterials. So, magnetic nanomaterials own special magnetic properties,such as high coercive force,superparamagnetism,low Curie temperature,single magnetic domain and so on. Therefore magnetic nanomaterials have become a hot area of research in recent years. Spinel type ferrite have been used in wide areas such as biomedicine,magnetic storage materials,catalytic agent and so on for their good electromagnetic properties and it is a kind of important magnetic nanomaterials.In this paper,the Fe3O4nanoparticles doped La3+and CoFe2O4nanoparticles have been prepared by sol-gel method respectively The structure and phase、the size and the shape、the magnetic properties of the nanoparticals prepared were analysised and studied by X-ray diffraction(XRD)、Scanning electron microscope(SEM)、 Physical property measurement system(PPMS),respectively. And parameters which influence chemical and physical properties of samples have been studied in order to find the experimental basis for the next work.The following results are obtained through the study and analyzing:(1) The preparation of the FesO4nanoparticles doped La3+:the prepared cycle of the Fe3O4nanoparticles doped La3+is shortened highly when using spontaneous combustion sol-gel method; the morphology of the nanoparticles is the best which are prepared thongh water bathing5h at80℃,calcinating5h at800℃。(2) The preparation of the CoFe2O4nanoparticles:CoFe2O4nanoparticles whose size is uniform have been synthtized though sol-gel method using polyving akohol(PVA) and polyethylene glycol(PEG) as dispersants and gelatas; And the size of nanoparticles prepared using PEG and PVA as dispersants and gelatas is20～40nm and～100nm respectively; the remanence ratio and the saturation magnetism of the nanoparticals using PEG is0.42and143.11emu/g respectively,it is mostly because that Co2+cations have been redistributed in A site and B site; and when the amount of PEG is different,the morphology and the magnetic properties is different,the morphology and the magnetic properties is the best when the amount of PEG is4g.更多还原