Morphology and magnetic flux distribution in superparamagnetic, single-crystalline Fe3O4 nanoparticle rings.
Morphology and magnetic flux distribution in superparamagnetic, single-crystalline Fe3O4 nanoparticle rings.
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DOI：
10.1063/1.4901008
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发表时间：
2014-11
影响因子：
4
通讯作者：
Y. Takeno;Y. Murakami;Takeshi Sato;T. Tanigaki;H. Park;D. Shindo;R. M. Ferguson;K. Krishnan
中科院分区：
文献类型：
--
作者：
Y. Takeno;Y. Murakami;Takeshi Sato;T. Tanigaki;H. Park;D. Shindo;R. M. Ferguson;K. Krishnan
本文研究了自组装环形式的Fe3O4纳米粒子的晶体取向与磁通量分布之间的关系。高分辨电子显微镜分析表明，该纳米粒子为单晶，高度单分散，平均直径为25 nm，未发现明显的晶格缺陷，如孪晶或堆积缺陷。对这些超顺磁性纳米颗粒环的电子全息研究表明，磁通线有明显的波动，这与纳米颗粒的磁晶各向异性的变化一致。这些观察结果为更深入地理解超小纳米颗粒的微磁性提供了有用的信息，其中磁偶极相互作用与磁各向异性竞争。
This study reports on the correlation between crystal orientation and magnetic flux distribution of Fe3O4 nanoparticles in the form of self-assembled rings. High-resolution transmission electron microscopy demonstrated that the nanoparticles were single-crystalline, highly monodispersed, (25 nm average diameter), and showed no appreciable lattice imperfections such as twins or stacking faults. Electron holography studies of these superparamagnetic nanoparticle rings indicated significant fluctuations in the magnetic flux lines, consistent with variations in the magnetocrystalline anisotropy of the nanoparticles. The observations provide useful information for a deeper understanding of the micromagnetics of ultrasmall nanoparticles, where the magnetic dipolar interaction competes with the magnetic anisotropy.