Unconventional Electronic and Magnetic Properties of Carbon-Based Nano-π-electron System

(1)在氧气浓度较低的气氛中进行热处理，在HOPG衬底上形成孔洞。得到的孔具有与之字形边缘和扶手椅边缘之间方向相关的几何形状。利用空穴的边缘，用超高真空扫描隧道显微镜研究了电子结构与边缘结构的相关性。利用电子束光刻和氧等离子体刻蚀技术在石墨烯薄层上形成了纳米带、纳米石墨烯岛、纳米孔洞。(3)研究了钾在纳米孔活性碳纤维(ACF)上吸附的磁性，并形成了三维无序的纳米石墨烯网络。在纳米孔中产生了两种钾物种：电荷转移物种与纳米石墨烯片层的π-电子相互作用；中性钾物种仅仅是Physisorbe…更多的d进入纳米孔。由于费米能量的上移，从钾到纳米茂的电荷转移降低了边缘态自旋的浓度。中性的钾物种形成反铁磁性团簇，其中的钾原子通过交换作用相互强烈耦合。(4)吸附在ACF纳米孔中的Ar原子机械地压缩沸点以下的纳米孔结构域，导致纳米层间距减小。距离的减小导致了边态自旋的反铁磁短程有序。(5)酸性分子被吸附到ACFS的纳米孔中，改变了边态自旋的磁性，电荷转移相互作用和机械效应的协同作用或竞争作用取决于其氧化能力。吸附在纳米孔中的盐酸通过机械作用来降低边缘态自旋的磁矩。具有氧化能力的硝酸根据酸中水的含量以一种复杂的方式改变边缘态自旋的磁性。较少

(1) Holes are created on HOPG substrates by heat-treatment in the atmosphere with a small oxygen concentration. The obtained holes have geometry with directional dependence between zigzag and armchair edges. Using the edges of the holes, the correlation of the electronic structure and the edge structure is investigated by means of UHV-STM. Around the graphene edges, a hexagonal superstructure deformed in three fold symmetry was observed.(2) Nanographene ribbons, nanographene islands, nanoholes on a graphene sheet are created using electron beam lithography and oxygen plasma etching technique with thin layer graphene.(3) The magnetic properties was investigated for potassium adsorbed into nanoporous activated carbon fibers (ACFs) which form 3D disordered network of nanographite domains. Two kinds of potassium species are created in the nanopores; charge transfer species electronically interacting with the π-electrons of nanpgraphene sheets and neutral potassium species merely physisorbe … More d into the nanopores. Charge transfer from the potassium to the nanographene reduces the concentration of the edge-state spins as a consequence of the upshift of the Fermi energy. The neutral potassium species form antiferromagnetic clusters, in which potassium atoms are coupled strongly with each other through exchange interactions.(4) The argon atoms adsorbed in the nanopores in ACFs mechanically compress the nanographite domains below the boiling point, resulting in the reduction of the inter-nanographene distance. The reduction of the distance induces the antiferromagnetic short range ordering of the edge-state spins in a nanographite domain.(5) The adsorption of acid molecules into the nanopores of ACFs modifies the magnetism of the edge-state spins in a manner, in which the charge transfer interaction and the mechanical effect works cooperatively or compete depending on their oxidation ability. Hydrochloric acid adsorbed in the nanopores works mechanically to reduce the magnetic moment of the edge-state spins. Nitric acid having the oxidation ability changes the magnetism of the edge-state spins in a complicated way depending on the content of water in the acid. Less