The mechanism of magnetism in stacked nanographite: theoretical study
The mechanism of magnetism in stacked nanographite: theoretical study
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DOI：
10.1088/0953-8984/13/6/309
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发表时间：
2001-02-12
影响因子：
2.7
通讯作者：
Harigaya, K
中科院分区：
文献类型：
--
作者：
Harigaya, K
纳米石墨系统，其中纳米级尺寸的石墨烯片被堆叠，显示出新颖的磁性，例如自旋玻璃样行为和在气体吸附过程中电子自旋共振线宽的变化。我们从理论上研究了锯齿形纳米石墨片的堆积效应，通过使用紧束缚模型与Hubbard样的现场相互作用。我们发现简单的A-A型和A-B型堆积之间的磁性有显著的差异。对于简单的堆叠，没有磁性解决方案。对于A-B堆叠，我们发现反铁磁的解决方案，强烈的就地排斥。局部磁矩往往存在于每层的边缘位置，由于在这些位置的波函数的大振幅。与实验的关系进行了讨论。
Nanographite systems, where graphene sheets of dimensions of the order of nanometres are stacked, show novel magnetic properties, such as spin-glass-like behaviours and change of electron spin-resonance linewidths in the course of gas adsorptions. We investigate stacking effects in zigzag nanographite sheets theoretically, by using a tight-binding model with Hubbard-like on-site interactions. We find a remarkable difference in magnetic properties between the simple A-A-type and A-B-type stackings. For the simple stacking, there are no magnetic solutions. For the A-B stacking, we find antiferromagnetic solutions for strong on-site repulsions. The local magnetic moments tend to exist at the edge sites in each layer due to the large amplitudes of the wavefunctions at these sites. Relations with experiments are discussed.