Wang D, Zhang Z, Zhu Z, Liang B
Institute of Nanomaterial &Nanostructure, Changsha University of Science and Technology, Changsha 410114, China.
1] Institute of Nanomaterial &Nanostructure, Changsha University of Science and Technology, Changsha 410114, China [2] School of Automotive &Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China.
Sci Rep. 2014 Dec 23;4:7587. doi: 10.1038/srep07587.
The magnetic structure and magnetic transport properties of hydrogen-passivated sawtooth zigzag-edge graphene nanoribbons (STGNRs) are investigated theoretically. It is found that all-sized ground-state STGNRs are ferromagnetic and always feature magnetic semiconductor properties, whose spin splitting energy gap E(g) changes periodically with the width of STGNRs. More importantly, for the STGNR based device, the dual spin-filtering effect with the perfect (100%) spin polarization and high-performance dual spin diode effect with a rectification ratio about 10(10) can be predicted. Particularly, a highly effective spin-valve device is likely to be realized, which displays a giant magnetoresistace (MR) approaching 10(10)%, which is three orders magnitude higher than the value predicted based on the zigzag graphene nanoribbons and six orders magnitude higher than previously reported experimental values for the MgO tunnel junction. Our findings suggest that STGNRs might hold a significant promise for developing spintronic devices.
从理论上研究了氢钝化锯齿形边缘石墨烯纳米带（STGNRs）的磁结构和磁输运性质。研究发现，所有尺寸的基态STGNRs都是铁磁性的，并且始终具有磁半导体性质，其自旋分裂能隙E(g)随STGNRs的宽度周期性变化。更重要的是，对于基于STGNR的器件，可以预测具有完美（100%）自旋极化的双自旋过滤效应和整流比约为10(10)的高性能双自旋二极管效应。特别地，有可能实现一种高效的自旋阀器件，其显示出接近10(10)%的巨磁阻（MR），这比基于锯齿形石墨烯纳米带预测的值高三个数量级，比先前报道的MgO隧道结的实验值高六个数量级。我们的研究结果表明，STGNRs在开发自旋电子器件方面可能具有重大前景。
