Tang Shaobin, Cao Xinrui
Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province, Gannan Normal University, Ganzhou 341000, China.
Phys Chem Chem Phys. 2014 Nov 14;16(42):23214-23. doi: 10.1039/c4cp03291h.
Hydrogenation and fluorination provide promising applications for tuning the properties of graphene-based nanomaterials. Using first-principles calculations, we investigate the electronic and magnetic properties of zigzag graphene nanoribbons (ZGNRs) supported on hydrogenated and fluorinated ZGNRs. Our results indicate that the support of zigzag graphane nanoribbon with its full width has less impact on the electronic and magnetic properties of ZGNRs, whereas the ZGNRs supported on fluorographene nanoribbons can be tuned to metal with almost degenerated ferro- and anti-ferromagnetic states due to the intrinsic polarization of substrate. The ZGNRs supported on zigzag hybrid fluorographene-graphane nanoribbons are spin-polarized half-semiconductors with distinct band gaps for spin-up and spin-down channels. Interestingly, in the absence of an external electric field, the spin-polarized band gaps of supported ZGNRs can be well modulated in the opposite direction by changing the ratio of fluorination to hydrogenation concentration in hybrid substrates. Furthermore, the ZGNRs supported on hybrid nanoribbons exhibit the half-semiconducting to half-metallic behavior transition as the interlayer spacing is gradually reduced, which is realized more easily for the hybrid support with a relatively wide fluorographene moiety compared to its narrow counterpart. Present results provide a novel way for designing substrate-supported graphene spintronic devices.
氢化和氟化在调控基于石墨烯的纳米材料性能方面具有广阔的应用前景。我们采用第一性原理计算方法，研究了氢化和氟化锯齿形石墨烯纳米带（ZGNRs）负载的锯齿形石墨烯纳米带的电学和磁学性质。结果表明，全宽锯齿形石墨烷纳米带的负载对ZGNRs的电学和磁学性质影响较小，而氟化石墨烯纳米带负载的ZGNRs由于衬底的固有极化，可被调控为具有几乎简并的铁磁和反铁磁态的金属。锯齿形氟化石墨烯 - 石墨烷混合纳米带负载的ZGNRs是自旋极化的半半导体，其自旋向上和自旋向下通道具有明显的带隙。有趣的是，在没有外部电场的情况下，通过改变混合衬底中氟化与氢化浓度的比例，可以很好地反向调制负载ZGNRs的自旋极化带隙。此外，随着层间距逐渐减小，混合纳米带负载的ZGNRs表现出从半半导体到半金属行为的转变，与窄部分的混合支撑相比，具有相对宽的氟化石墨烯部分的混合支撑更容易实现这种转变。目前的结果为设计衬底支撑的石墨烯自旋电子器件提供了一种新方法。
