Department of Physics and High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, USA.
ACS Nano. 2011 Feb 22;5(2):1012-7. doi: 10.1021/nn1024175. Epub 2011 Jan 13.
We examine the magnetic properties of two-dimensional graphene with topological line defect using first-principles calculations and predict a weak ferromagnetic ground state with spin-polarized electrons localized along the extended line defect. Our results show that tensile strain along the zigzag direction can greatly enhance local magnetic moments and ferromagnetic stability of the system. In sharp contrast, tensile strain applied along the armchair direction quickly diminishes these magnetic moments. A detailed analysis reveals that this intriguing magnetism modulation by strain stems from the redistribution of spin-polarized electrons induced by local lattice distortion. It suggests a sensitive and effective way to control magnetic properties of graphene which is critical for its applications in nanoscale devices.
我们使用第一性原理计算研究了具有拓扑线缺陷的二维石墨烯的磁性，并预测了一种具有沿扩展线缺陷局域化的自旋极化电子的弱铁磁基态。我们的结果表明，沿锯齿形方向的拉伸应变可以极大地增强系统的局域磁矩和铁磁稳定性。与此形成鲜明对比的是，沿扶手椅方向施加的拉伸应变会迅速减小这些磁矩。详细分析表明，应变引起的局域晶格畸变导致自旋极化电子的重新分布，从而引起这种有趣的磁调制。这为控制石墨烯的磁性提供了一种敏感而有效的方法，这对于其在纳米器件中的应用至关重要。
