Zheng Anmin, Gao Guoying, Huang Hai, Gao Jinhua, Yao Kailun
School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China.
Phys Chem Chem Phys. 2017 May 31;19(21):13650-13657. doi: 10.1039/c7cp01002h.
Using density-functional theory, we investigate the electronic and magnetic properties of an adatom (Na, Cu and Fe) on ABA- and ABC-stacked (Bernal and rhombohedral) trilayer graphenes. In particular, we study the influence of an applied gate voltage on magnetism, as it modifies the electronic states of the trilayer graphene (TLG) as well as changes the adatom spin states. Our study performed for a choice of three different adatoms (Na, Cu, and Fe) shows that the nature of adatom-graphene bonding evolves from ionic to covalent in moving from an alkali metal (Na) to a transition metal (Cu or Fe). Applying an external electric field (EEF) to TLG systems with different stacking orders results in the transition between high- and low-spin states in the latter case (Cu, Fe) and induces a little of magnetism in the former (Na) without magnetism in the absence of an external electric field. Our study would be useful for controlled adatom magnetism and (organic) spintronic applications in nanotechnology.
利用密度泛函理论，我们研究了吸附原子（钠、铜和铁）在ABA堆叠和ABC堆叠（伯纳尔堆叠和菱面体堆叠）的三层石墨烯上的电子和磁性特性。特别地，我们研究了外加栅极电压对磁性的影响，因为它会改变三层石墨烯（TLG）的电子态并改变吸附原子的自旋态。我们针对三种不同的吸附原子（钠、铜和铁）进行的研究表明，从碱金属（钠）到过渡金属（铜或铁），吸附原子与石墨烯的键合性质从离子键演变为共价键。对具有不同堆叠顺序的TLG系统施加外部电场（EEF），会导致后一种情况（铜、铁）中高自旋态和低自旋态之间的转变，并在前一种情况（钠）中在没有外部电场时无磁性的情况下诱导出一点磁性。我们的研究将有助于纳米技术中可控的吸附原子磁性和（有机）自旋电子学应用。
