Effects of annealing temperature on the structure and magnetic properties of the L10-FePt nanoparticles synthesized by the modified sol-gel method
Effects of annealing temperature on the structure and magnetic properties of the L10-FePt nanoparticles synthesized by the modified sol-gel method
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DOI：
10.1016/j.powtec.2013.01.069
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发表时间：
2013-05-01
影响因子：
5.2
通讯作者：
Yan, Yongsheng
中科院分区：
文献类型：
--
作者：
Liu, Yang;Jiang, Yuhong;Yan, Yongsheng
采用溶胶-凝胶法制备了有序面心四边形（FCT） FePt纳米颗粒。讨论了退火温度（400、500、600和700℃）与FePt NPs结构和磁性能的关系。并从原子扩散的角度给出了可能的生长机理。差热分析（DTA）表明，在600℃以下的温度下，各种水分子脱水，有机基团燃烧/分解，x射线衍射（XRD）图显示，当退火温度升高到500℃时，形成L1(0) FePt NPs，并出现超晶格峰（001）和（110）。此外，根据XRD结果，我们发现随着退火温度的升高，化学有序参数增加。透射电子显微镜（TEM）图像显示，在700℃下产生的NPs平均直径为14 nm。经700℃退火的样品的选择区电子衍射（SAED）图进一步证实了L1(0) FePt NPs的合成。能谱分析表明，FePt NPs中不存在杂质相。样品在700℃退火时获得了最大矫顽力（10,148 Oe）。
The ordered face-centered tetragonal (FCT) FePt nanoparticles (NPs) were successfully synthesized by the modified sol-gel method. The relationship between the annealing temperature (400, 500, 600 and 700 degrees C) and the structure and magnetic properties of the FePt NPs was discussed. And the possible growth mechanism was given in terms of atomic diffusion. Differential thermal analysis (DTA) showed the dehydration of various water molecules and combustion/decomposition of organic groups at the temperature below 600 degrees C. The X-ray diffraction (XRD) patterns revealed that as the annealing temperature increased to 500 degrees C, the L1(0) FePt NPs were formed as was indicated by the appearance of superlattice peaks (001) and (110). Moreover, based on the XRD results, we found that the chemical order parameters increased with the increase of the annealing temperature. The transmission electron microscope (TEM) images showed that the NPs produced at 700 degrees C had a mean diameter of 14 nm. The selected area electron diffraction (SAED) patterns of the samples annealed at 700 degrees C further demonstrated the synthesis of the L1(0) FePt NPs. The energy dispersive X-ray spectroscopy (EDS) analysis showed that no impurity phases existed in FePt NPs. The maximum coercivity (10,148 Oe) was obtained for the sample annealed at 700 degrees C. (C) 2013 Elsevier B.V. All rights reserved.