School of Science, Hubei University for Nationalities, Enshi, 445000, People's Republic of China.
Sci Rep. 2018 Jan 17;8(1):927. doi: 10.1038/s41598-018-19632-3.
Metal-free magnetism and spin caloritronics are at the forefront of condensed-matter physics. Here, the electronic structures and thermal spin-dependent transport properties of armchair graphene nanoribbons (N-AGNRs), where N is the ribbon width (N = 5-23), are systematically studied. The results show that the indirect band gaps exhibit not only oscillatory behavior but also periodic characteristics with E > E > E (E , E and E are the band gaps energy) for a certain integer p, with increasing AGNR width. The magnetic ground states are ferromagnetic (FM) with a Curie temperatures (T ) above room temperature. Furthermore, the spin-up and spin-down currents with opposite directions, generated by a temperature gradient, are almost symmetrical, indicating the appearance of the perfect spin-dependent Seebeck effect (SDSE). Moreover, thermally driven spin currents through the nanodevices induced the spin-Seebeck diode (SSD) effect. Our calculation results indicated that AGNRs can be applied in thermal spin nanodevices.
无金属磁性和自旋热电子学是凝聚态物理的前沿领域。在这里，我们系统地研究了扶手椅型石墨烯纳米带（N-AGNRs）的电子结构和热自旋相关输运性质，其中 N 是纳米带的宽度（N=5-23）。结果表明，间接带隙不仅表现出振荡行为，而且随着 AGNR 宽度的增加，对于某个整数 p，还表现出与 E > E > E（E 、E 和 E 分别是带隙能量）具有周期性特征。磁基态是铁磁（FM），居里温度（T ）高于室温。此外，由温度梯度产生的具有相反方向的自旋向上和自旋向下电流几乎是对称的，这表明出现了完美的自旋相关塞贝克效应（SDSE）。此外，通过纳米器件的热驱动自旋流诱导了自旋-塞贝克二极管（SSD）效应。我们的计算结果表明，AGNRs 可应用于热自旋纳米器件。
