A novel approach to the synthesis of CoPt magnetic nanoparticles
A novel approach to the synthesis of CoPt magnetic nanoparticles
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DOI：
10.1088/0022-3727/44/29/295003
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发表时间：
2011-07
期刊：
影响因子：
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通讯作者：
Y. J. Zhang;Y. Yang;Y. Liu;Y. Wang;L. L. Yang-L.;M. Wei;H. Fan;H. Zhai;X. Y. Liu;
中科院分区：
文献类型：
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作者：
Y. J. Zhang;Y. Yang;Y. Liu;Y. Wang;L. L. Yang-L.;M. Wei;H. Fan;H. Zhai;X. Y. Liu;
采用溶胶-凝胶法合成了具有面心四面体（FCT）结构的L10 CoPt纳米粒子。差热分析表明，在低于600 °C的温度下，各种水分子脱水，有机基团分解/燃烧，Co和Pt在700 °C下熔化。X-射线衍射结果表明，从面心立方过渡到FCT相，并随着温度的升高，颗粒尺寸增加。透射电子显微镜（TEM）图像显示，获得了高度单分散的颗粒。高分辨率TEM（HRTEM）图像显示在高于600 °C的温度下出现L10有序相。X射线光电子能谱扫描表明，在检测限内没有检测到磁性杂质。在800 °C下加热的样品获得了最大矫顽力（353 344 A m−1）。讨论了温度与结构之间的关系，并从原子扩散的角度给出了可能的生长机制。
L10 CoPt nanoparticles with face-centred tetragonal (FCT) structure are synthesized by the sol–gel method. Differential thermal analyses show the dehydration of various water molecules and decomposition/combustion of organic groups at a temperature below 600 °C and melting of Co and Pt at 700 °C. X-ray diffraction results show a transition from face-centred cubic to the FCT phase and an increase in particle size with increasing temperature. Transmission electron microscope (TEM) images show that highly monodisperse particles are obtained. High-resolution TEM (HRTEM) images reveal the appearance of L10 ordered phase at temperatures above 600 °C. The survey scans of x-ray photoelectron spectroscopy show that no magnetic impurity is detected within the detection limit. The maximum coercivity (353 344 A m−1) is obtained for the samples heated at 800 °C. The relationship between the temperature and the structure is discussed and the possible growth mechanism is given in terms of atomic diffusion.