2014/01/18 by Norio Ota, Ota, Norio
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.1401.4504
6 pages, 11 figures,3 tables. arXiv admin note: substantial text overlap with arXiv:1307.2960
arxiv created 2014/01/18 · arxiv updated 2014/01/21
Magnetic properties and band characteristics of graphene-nano-ribbon (GNR) modified by Fe, Co, and Ni were analyzed by the first principles DFT calculation. Typical unit cell is [C32H2Fe1], [C32H2Co1] and [C32H2Ni1] respectively. The most stable spin state was Sz=4/2 for Fe-modified GNR, whereas Sz=3/2 for Co-case and Sz=2/2 for Ni-case. Atomic magnetic moment of Fe, Co and Ni were 3.63, 2.49 and 1.26 μB, which were reduced values than that of atomic Hund-rule due to magnetic coupling with graphene network. There is a possibility for a ferromagnetic Fe, Co and Ni spin array through an interaction with carbon pi-conjugated spin system. By expanding a unit cell of Co-modified case as [C96H6Co3], ferromagnetic like spin state and ferrimagnetic like one were compared. It was concluded that ferromagnetic state was more stable magnetic state. Band calculations of Co-modified case show half-metal like structure with relatively large band gap (0.55eV) for up-spin, whereas small gap (0.05eV) for down-spin. This suggested a capability of spintronics application like a spin fiter.