论文总字数：27604字

摘 要

化学有序相FePt（又称L10相或面心四方FCT结构FePt）纳米颗粒在未来高密度磁记录材料、催化剂材料等领域具有良好的应用前景，但目前有序相FePt纳米颗粒的制备技术尚不成熟。有序相FePt需在700℃以上的高温下合成，在高温过程中需要防止纳米颗粒的团聚和烧结长大。油相热分解法或溶胶-凝胶法等化学法由于制备温度太低，难以生成有序相，而磁控溅射等物理法的制备效率又过低。近几年出现的水溶性盐隔离无序相FePt前驱体法的制备工艺太过复杂、难以实现规模化生产。因此，能否找到一种规模化制备有序相FePt纳米颗粒的简便技术，决定了此材料是否能真正得到工业化应用。

本文探索了一种新型的水溶性盐隔离法，使用铁盐和氯铂酸的混合溶液浸渍氯化钠盐，干燥后高温还原得到FePt纳米颗粒，此方法制备工艺简单，原材料成本低廉，且易于实现工业化。

本文主要研究了溶剂、前驱体浓度、表面活性剂和浸渍时间等因素对FePt纳米颗粒尺寸及形貌的影响，并成功制备出尺寸细小、分散性好的L10-FePt纳米颗粒，粒径分布在5-30nm。研究表明，溶剂为异丙醇时得到的FePt纳米颗粒的粒径更细小、均匀；减小前驱体浓度时，颗粒的粒径明显减小，均匀性也有所改善；浸渍时间为24小时的样品得到的FePt纳米颗粒尺寸最均匀；添加表面活性剂PEG2000所得到的FePt纳米颗粒的结晶性更佳。

关键词：有序相，铁铂纳米颗粒，水溶性盐隔离法

Abstract

Chemically ordered phase FePt (also known as L10 phase or face centered quaternary FCT structure FePt) nanoparticles have a good application prospect in the field of high-density magnetic recording materials and catalyst materials in the future, but the preparation technology of ordered phase FePt nanoparticles is not mature at present. Ordered phase FePt are under the high temperature of 700 ℃ above, in the process of high temperature to prevent agglomeration of nanoparticles and sintering grew up. Chemical methods such as oil-phase thermal decomposition method or sol-gel method are difficult to generate ordered phases due to low preparation temperature, while physical methods such as magnetron sputtering have too low preparation efficiency. In recent years, the preparation process of disordered phase FePt with water-soluble salt isolation is too complex to realize large-scale production. Therefore, whether a simple and convenient technology can be found for large-scale preparation of ordered phase FePt nanoparticles determines whether the material can be truly applied in the industrial field.

In this paper, a new water-soluble salt isolation method was explored, in which the mixed solution of iron salt and chloroplatinic acid was impregnated with sodium chloride, and the FePt nanoparticles were reduced at high temperature after drying.

In this paper, the effects of solvent, precursor concentration, surfactant and immersion time on the size and morphology of FePt nanoparticles were studied, and l10-fept nanoparticles with fine size and good dispersion were successfully prepared, with particle size distribution of 5-30nm. The result is that the size of FePt nanoparticles was smaller and more uniform when the solvent was isopropanol. When the precursor concentration was reduced, the particle size was obviously reduced and the uniformity was improved. The size of FePt nanoparticles was the most uniform when the sample was impregnated for 24 hours. FePt nanoparticles with surfactant PEG2000 had better crystallinity.

KEY WORDS: iron-platinum nanoparticles, water-soluble salt isolation method

目 录

摘要……………………………………………………………………………………………………………Ⅰ

Abstract……………………………………………………………………………………………………… Ⅱ

第一章 绪论 1

1.1引言 1

1.2磁性材料概述 1

1.3FePt纳米材料的结构及应用 4

1.4FePt纳米材料的研究现状 6

1.5选题内容及目的 11

第二章 研究内容与方法 12

2.1实验路线 12

2.2实验材料及仪器 12

2.3实验原理及内容 14

2.4结构与形貌分析 15

2.5 性能检测 16

第三章 水溶性盐隔离法制备铁铂纳米颗粒 17

3.1溶剂种类对L1₀-FePt颗粒尺寸及形貌的影响 17

3.2浸渍时间对L1₀-FePt颗粒尺寸及形貌的影响 19

3.3前驱体浓度对L1₀-FePt颗粒尺寸及形貌的影响 21

3.4表面活性剂对L1₀-FePt颗粒尺寸及形貌的影响 23

3.5磁性能分析 27

第四章 结论 29

参考文献 30

致 谢 33

第一章 绪论

1.1引言

FePt二元合金是一种性能十分优异的磁功能材料，其中具有大磁晶各向异性的L1₀-FePt（L1₀或面心四方FCT结构FePt）纳米颗粒，因其具备高的矫顽力、极小的超顺磁临界尺寸和良好的化学热稳定性，被认为是新一代高密度磁存储材料的，应用前景十分广阔^[1]。因此，制备高化学有序度的 L1₀-FePt 一直以来都是国内外学者们研究的焦点。

近些年来，通过人们的不断研究，目前FePt纳米颗粒的制备方法主要有高温热分解法、一步固相法、溶胶-凝胶法等，目前已有的制备方法都还不完善，制备过程需多部合成，工艺复杂，高温煅烧过程中难以避免颗粒的团聚和烧结长大，并且原料成本高、难以实现规模化生产。

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