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

(1)通过在具有小氧浓度的气氛中热处理在HOPG衬底上产生孔。所获得的孔具有在锯齿形边缘和扶手椅边缘之间具有方向依赖性的几何形状。利用UHV-STM研究了空穴的边缘结构与电子结构的相关性。在石墨烯边缘周围，观察到以三重对称变形的六边形超结构。(2)利用电子束光刻和氧等离子体刻蚀技术在石墨烯片上制备纳米石墨烯带、纳米石墨烯岛、纳米孔。(3)研究了纳米多孔活性炭纤维（ACF）吸附钾离子后的磁性。在纳米孔中产生了两种钾物种：与纳米石墨烯片的π电子电子相互作用的电荷转移物种和仅物理吸附的中性钾物种。 关于我们 d进入纳米孔。从钾到纳米石墨烯的电荷转移降低了边缘态自旋的浓度，这是费米能量上移的结果。中性钾物种形成反铁磁团簇，其中钾原子通过交换相互作用彼此强烈耦合。(4)吸附在ACF中的纳米孔中的氩原子在沸点以下机械地压缩纳米石墨域，导致纳米石墨烯间距离的减小。距离的减小导致了纳米石墨畴中边态自旋的反铁磁短程有序。(5)酸分子吸附到ACF的纳米孔中以电荷转移相互作用和机械效应根据其氧化能力协同或竞争的方式改变边缘态自旋的磁性。吸附在纳米孔中的盐酸以机械方式起作用以减小边缘态自旋的磁矩。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