Electronic structure of Li@C; Photoelectron spectroscopy of the Li@C[PF] salt and STM of the single Li@C molecules on Cu(111)

Yamada, Yoichi*; Kuklin, A. V.*; Sato, Sho*; Esaka, Fumitaka; Sumi, Naoya*; Zhang, C.*; Sasaki, Masahiro*; Kwon, E.*; Kasama, Yasuhiko*; Avramov, P. V.*; et al.

Carbon, 133, p.23 - 30, 2018/07

https://doi.org/10.1016/j.carbon.2018.02.106

We report first STM observation of the Li ion endohedral C, which is of a new class of endohedral fullerenes, prepared by means of evaporation of high-purity Li@C[PF] salt in ultra-high vacuum. Prior to the STM measurements, the electronic structure of Li@C in the Li@C[PF] salt was also precisely determined. In the salt, it is shown that Li and PF have nearly single positive and negative charge, respectively, and the C cage is nearly neutral, suggesting that Li@C in the salt retains its original electronic state.

Contact-induced spin polarization in BNNT(CNT)/TM (TM=Co, Ni)nanocomposites

Kuzubov, A. A.*; Kovaleva, E. A.*; Avramov, P. V.*; Kuklin, A. V.*; Mikhaleva, N. S.*; Tomilin, F. N.*; Sakai, Seiji; Entani, Shiro; Matsumoto, Yoshihiro*; Naramoto, Hiroshi*

Journal of Applied Physics, 116(8), p.084309_1 - 084309_4, 2014/08

https://doi.org/10.1063/1.4894157

Contact-induced spin polarization of monolayer hexagonal boron nitride on Ni(111)

Otomo, Manabu; Yamauchi, Yasushi*; Kuzubov, A. A.*; Eliseeva, N. S.*; Avramov, P.*; Entani, Shiro; Matsumoto, Yoshihiro; Naramoto, Hiroshi*; Sakai, Seiji

Applied Physics Letters, 104(5), p.051604_1 - 051604_4, 2014/02

https://doi.org/10.1063/1.4863324

Hexagonal boron nitride (h-BN) is a promising barrier material for graphene spintronics. In this study, spin-polarized metastable de-excitation spectroscopy (SPMDS) is employed to study the spin-dependent electronic structure of monolayer h-BN on Ni(111). The extreme surface sensitivity of SPMDS enables us to elucidate a partial filling of the in-gap states of h-BN without any superposition of Ni 3 signals. The in-gap states are shown to have a considerable spin polarization parallel to the majority spin of Ni. The positive spin polarization is attributed to the - hybridization and the effective spin transfer to the nitrogen atoms at the h-BN/Ni(111) interface.

High spin polarization at the Fe/C interface in the Fe-doped C film

Sakai, Seiji; Matsumoto, Yoshihiro; Otomo, Manabu; Entani, Shiro; Avramov, P.; Sorokin, P. B.*; Naramoto, Hiroshi*

Synthetic Metals, 173, p.22 - 25, 2013/06

https://doi.org/10.1016/j.synthmet.2012.10.027

Intrinsic edge asymmetry in narrow zigzag hexagonal heteroatomic nanoribbons causes their subtle uniform curvature

Avramov, P.; Fedorov, D. G.*; Sorokin, P. B.*; Sakai, Seiji; Entani, Shiro; Otomo, Manabu; Matsumoto, Yoshihiro; Naramoto, Hiroshi*

Journal of Physical Chemistry Letters (Internet), 3(15), p.2003 - 2008, 2012/08

https://doi.org/10.1021/jz300625t

Bias voltage dependence of tunneling magnetoresistance in granular C-Co films with current-perpendicular-to-plane geometry

Sakai, Seiji; Mitani, Seiji*; Matsumoto, Yoshihiro; Entani, Shiro; Avramov, P.; Otomo, Manabu; Naramoto, Hiroshi*; Takanashi, Koki

Journal of Magnetism and Magnetic Materials, 324(12), p.1970 - 1974, 2012/06

https://doi.org/10.1016/j.jmmm.2012.01.033

Precise control of single- and bi-layer graphene growths on epitaxial Ni(111) thin films

Entani, Shiro; Matsumoto, Yoshihiro; Otomo, Manabu; Avramov, P.; Naramoto, Hiroshi*; Sakai, Seiji

Journal of Applied Physics, 111(6), p.064324_1 - 064324_6, 2012/03

https://doi.org/10.1063/1.3694662

analysis was performed on the graphene growth in ultrahigh vacuum chemical vapor deposition by exposing the epitaxial Ni(111) thin film to benzene vapor at 873 K. It is shown that the highly uniform single- and bi-layer graphenes can be synthesized by the control of benzene exposure in the range of 10-10 langmuirs, reflecting a change in the graphene growth-rate by three orders of magnitude in between the first and second layer. Electron energy loss spectroscopy measurements of single- and bi-layer graphenes indicates that the interface interaction between bi-layer graphene and Ni(111) is weakened in comparison with that between single-layer graphene and Ni(111). It is also clarified from the micro-Raman analysis that the structural and electrical uniformities of the graphene film transformed on a SiO substrate are improved remarkably under the specific exposure conditions at which the growths of single- and bi-layer graphenes are completed.

Relative isomer abundance of fullerenes and carbon nanotubes correlates with kinetic stability

Fedorov, A. S.*; Fedorov, D. A.*; Kuzubov, A. A.*; Avramov, P.; Nishimura, Yoshifumi*; Irle, S.*; Witek, H. A.*

Physical Review Letters, 107(17), p.175506_1 - 175506_5, 2011/10

https://doi.org/10.1103/PhysRevLett.107.175506

LC-DFT study of graphene, multilayer graphenes and graphite

Avramov, P.; Sakai, Seiji; Entani, Shiro; Matsumoto, Yoshihiro; Naramoto, Hiroshi*

Chemical Physics Letters, 508(1-3), p.86 - 89, 2011/05

https://doi.org/10.1016/j.cplett.2011.04.016

Influence of size effect on the electronic and elastic properties of diamond films with nanometer thickness

Chernozatonskii, L. A.*; Sorokin, P. B.*; Kuzubov, A. A.*; Sorokin, B. P.*; Kvashnin, A. G.*; Kvashnin, D. G.*; Avramov, P.; Yakobson, B. I.*

Journal of Physical Chemistry C, 115(1), p.132 - 136, 2011/01

https://doi.org/10.1021/jp1080687