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

(1)在氧气浓度较低的大气中热处理，在HOPG基板上形成孔洞。所获得的孔具有几何形状，在锯齿形和扶手椅边之间具有方向依赖性。利用特高压- stm技术，利用空穴的边缘，研究了电子结构与边缘结构的相关性。在石墨烯边缘周围，观察到三重对称变形的六边形上部结构。(2)利用电子束光刻和氧等离子体刻蚀技术，在石墨烯薄片上制备纳米石墨烯带、纳米石墨烯岛和纳米空穴。(3)研究了钾吸附在纳米孔活性炭纤维（ACFs）上形成纳米石墨畴三维无序网络的磁性能。在纳米孔中产生了两种钾；电荷转移物质与纳米石墨烯片上的π电子相互作用，而中性钾物质只是物理吸附在纳米孔中。由于费米能量的上升，电荷从钾转移到纳米石墨烯降低了边缘态自旋的浓度。中性钾形成反铁磁簇，其中钾原子通过交换相互作用彼此强耦合。(4)吸附在ACFs纳米孔中的氩原子在沸点以下机械压缩纳米石墨畴，导致纳米石墨烯间距离减小。距离的减小引起了纳米石墨畴中边缘态自旋的反铁磁短程有序。(5)酸分子在ACFs纳米孔中的吸附改变了边缘态自旋的磁性，根据它们的氧化能力，电荷转移相互作用和机械效应协同或竞争。吸附在纳米孔中的盐酸通过机械作用降低了边缘态自旋的磁矩。具有氧化能力的硝酸会根据酸中水的含量以复杂的方式改变边缘态自旋的磁性。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