Ferromagnetism induced by intrinsic defects and boron substitution in single-wall SiC nanotubes.
Ferromagnetism induced by intrinsic defects and boron substitution in single-wall SiC nanotubes.
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DOI：
10.1021/jp109470r
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发表时间：
2011-09
期刊：
影响因子：
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通讯作者：
Yongjia Zhang;H. Qin;E. Cao;Feng Gao;Hua Liu;Jifan Hu
中科院分区：
文献类型：
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作者：
Yongjia Zhang;H. Qin;E. Cao;Feng Gao;Hua Liu;Jifan Hu
基于密度泛函理论（DFT）方法，研究了具有不同空位和硼取代的扶手椅型（4，4）和锯齿型（8，0）单壁SiC纳米管的磁性和电子结构.计算结果表明，Si空位可以在扶手椅型（4，4）和锯齿型（8，0）单壁SiC纳米管中产生磁矩，磁矩主要来自Si空位周围C原子的p轨道，导致铁磁耦合.而C空位只能在扶手椅型（4，4）单壁SiC纳米管中产生磁矩，磁矩主要来源于Si p电子的极化，导致反铁磁耦合.此外，对于两种单壁SiC纳米管，都可以通过硼原子取代碳原子来诱导磁矩。当两个硼原子位于最近的空位时，两种单壁Si（C，B）纳米管都表现出反铁磁耦合。
On the basis of density functional theory (DFT) methods, we study the magnetic properties and electronic structures of the armchair (4, 4) and zigzag (8, 0) single-wall SiC nanotubes with various vacancies and boron substitution. The calculation results indicate that a Si vacancy could induce the magnetic moments in both armchair (4, 4) and zigzag (8, 0) single-wall SiC nanotubes, which mainly arise from the p orbital of C atoms surrounding Si vacancy, leading to the ferromagnetic coupling. However, a C vacancy could only bring about the magnetic moment in armchair (4, 4) single-wall SiC nanotube, which mainly originates from the polarization of Si p electrons, leading to the antiferromagnetic coupling. In addition, for both kinds of single-wall SiC nanotubes, magnetic moments can be induced by a boron atom substituting for C atom. When two boron atoms locate nearest neighbored, both kinds of single-wall Si(C, B) nanotubes exhibit antiferromagnetic coupling.