Orbital and spin magnetic moments of transforming one-dimensional iron inside metallic and semiconducting carbon nanotubes
Orbital and spin magnetic moments of transforming one-dimensional iron inside metallic and semiconducting carbon nanotubes
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DOI：
10.1103/physrevb.87.195435
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发表时间：
2013-05-20
影响因子：
3.7
通讯作者：
Shiozawa, Hidetsugu
中科院分区：
文献类型：
--
作者：
Briones-Leon, Antonio;Ayala, Paola;Shiozawa, Hidetsugu
利用局域X射线磁圆二色性（XMCD）和体超导量子干涉仪（SQUID）研究了金属和半导体碳纳米管中铁的轨道和自旋磁性。铁-纳米管混合物最初是二茂铁填充的不同金属性的单壁碳纳米管（SWCNT）。我们发现，二茂铁的分子轨道相互作用不同的单壁碳纳米管的不同金属没有显着的XMCD响应。在升高的温度下，二茂铁分子彼此反应形成纳米团簇。在不同的磁场下的XMCD显示，封装的铁的轨道和/或自旋磁矩的急剧改变，作为向1D集群的转换发生。轨道和自旋磁矩都被发现是在填充的半导体纳米管比在金属样品中更大。这可能意味着封装材料的磁极化取决于管的金属性。从铁的3d磁矩和SQUID测量的体磁性之间的比较，我们得出结论，离域磁性占主导地位的这些一维混合纳米结构的磁性。
The orbital and spin magnetic properties of iron inside metallic and semiconducting carbon nanotubes are studied by means of local x-ray magnetic circular dichroism (XMCD) and bulk superconducting quantum interference device (SQUID). The iron-nanotube hybrids are initially ferrocene filled single-walled carbon nanotubes (SWCNT) of different metallicities. We show that the ferrocene's molecular orbitals interact differently with the SWCNT of different metallicities with no significant XMCD response. At elevated temperatures the ferrocene molecules react with each other to form cementite nanoclusters. The XMCD at various magnetic fields reveal that the orbital and/or spin magnetic moments of the encapsulated iron are altered drastically as the transformation to the 1D clusters takes place. The orbital and spin magnetic moments are both found to be larger in filled semiconducting nanotubes than in the metallic sample. This could mean that the magnetic polarization of the encapsulated material depends on the metallicity of the tubes. From a comparison between the iron 3d magnetic moments and the bulk magnetism measured by SQUID, we conclude that the delocalized magnetisms dominate the magnetic properties of these 1D hybrid nanostructures.