Direct formation of L10 FePt in as-cast FePt-based magnetic nanocomposite ribbons without post-synthesis annealing
Direct formation of L10 FePt in as-cast FePt-based magnetic nanocomposite ribbons without post-synthesis annealing
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DOI：
10.1088/0022-3727/44/36/365002
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发表时间：
2011-09-14
影响因子：
3.4
通讯作者：
Crisan, O.
中科院分区：
文献类型：
--
作者：
Crisan, A. D.;Crisan, O.
合成了一种新型的纳米复合FePt基交换耦合磁体，并对其结构和磁性进行了表征。我们报告的第一次直接形成的L1（0）FePt相，而不需要在Fe-Pt基的熔纺薄带的合成后退火程序，通过传统的熔融纺丝方法获得。研究了Fe-Pt-Ag-B快淬薄带的结构和磁性能，并通过XRD和磁测量证实了铸态Fe-Pt-Ag-B快淬薄带中存在L1（0）有序相。通过扫描透射电子显微镜成像观察到由分散在软磁基质内的细小、均匀分散的22-24 nm FePt晶粒组成的微观结构。从铸态薄带的270 K磁滞回线确定了高达727 kAm（-1）的矫顽力、约1.2 T的饱和磁化强度和约87 kJm（-3）的能量积，即使没有进一步的退火处理，也使FePt基纳米复合磁体薄带成为最好的纳米复合磁体薄带之一。
A novel nanocomposite FePt-based exchange-coupled magnet has been synthesized and structurally and magnetically characterized. We report for the first time the direct formation of the L1(0) FePt phase without the need for post-synthesis annealing procedures in Fe-Pt-based melt-spun ribbons, obtained by a conventional melt spinning method. The structure and magnetic properties are investigated and the occurrence of the L1(0) ordered phase in the as-cast state of Fe-Pt-Ag-B melt-spun ribbons is confirmed by XRD and magnetic measurements. A microstructure consisting of fine, uniformly dispersed, 22-24 nm FePt grains dispersed within a soft magnetic matrix is observed by scanning transmission electron microscopy imaging. Coercive fields as high as 727 kAm(-1), saturation magnetization of about 1.2 T and energy product around 87 kJm(-3) are determined from 270 K hysteresis loops of the as-cast ribbons, making one of the best FePt-based nanocomposite magnet ribbons even without further annealing treatments.