Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 333

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Synchrotron X-ray standing wave Characterization of atomic arrangement at interface between transferred graphene and $$alpha$$-Al$$_{2}$$O$$_{3}$$(0001)

Entani, Shiro*; Honda, Mitsunori; Naramoto, Hiroshi*; Li, S.*; Sakai, Seiji*

Surface Science, 704, p.121749_1 - 121749_6, 2021/02

 Times Cited Count:5 Percentile:33.23(Chemistry, Physical)

Graphene is expected to be one of the most promising materials for nanoelectronics and spintronics. In most graphene-based devices, the graphene channel is placed on insulating substrates. Therefore, the study of inter-facial interactions between graphene and the insulator surface is of critical importance. In this study, the vertical arrangement of graphene which is transferred on $$alpha$$-Al$$_{2}$$O$$_{3}$$(0001) has been studied by normal incidence X-ray standing wave (NIXSW) technique. The analysis of the NIXSW profile reveals that the graphene layer is located at 3.57 (${AA}$) above the $$alpha$$-Al$$_{2}$$O$$_{3}$$(0001) surface, which is larger than the interlayer distance of graphite at 3.356 (${AA}$). Micro- Raman spectroscopy shows that the transferred graphene has a limited spatial distribution of hole concentration. The present study shows that transferred graphene on the sapphire substrate followed by vacuum-annealing has an atomically flat surface free from residual contaminations such as organic compounds and there occurs the hole-doping in graphene.

Journal Articles

Effective adsorption and collection of cesium from aqueous solution using graphene oxide grown on porous alumina

Entani, Shiro*; Honda, Mitsunori; Shimoyama, Iwao; Li, S.*; Naramoto, Hiroshi*; Yaita, Tsuyoshi; Sakai, Seiji*

Japanese Journal of Applied Physics, 57(4S), p.04FP04_1 - 04FP04_4, 2018/04

 Times Cited Count:3 Percentile:13.53(Physics, Applied)

Journal Articles

Magnetotransport properties of a few-layer graphene-ferromagnetic metal junctions in vertical spin valve devices

Entani, Shiro; Naramoto, Hiroshi*; Sakai, Seiji

Journal of Applied Physics, 117(17), p.17A334_1 - 17A334_4, 2015/05

 Times Cited Count:21 Percentile:63.75(Physics, Applied)

Journal Articles

Contracted interlayer distance in graphene/sapphire heterostructure

Entani, Shiro; Antipina, L. Y.*; Avramov, P.*; Otomo, Manabu*; Matsumoto, Yoshihiro*; Hirao, Norie; Shimoyama, Iwao; Naramoto, Hiroshi*; Baba, Yuji; Sorokin, P. B.*; et al.

Nano Research, 8(5), p.1535 - 1545, 2015/05

 Times Cited Count:28 Percentile:72.30(Chemistry, Physical)

Journal Articles

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

 Times Cited Count:9 Percentile:36.99(Physics, Applied)

Journal Articles

Atomic structure and physical properties of fused porphyrin nanoclusters

Avramov, P. V.*; Kuzubov, A. A.*; Sakai, Seiji; Otomo, Manabu*; Entani, Shiro; Matsumoto, Yoshihiro*; Eleseeva, N. S.*; Pomogaev, V. A.*; Naramoto, Hiroshi*

Journal of Porphyrins and Phthalocyanines, 18(7), p.552 - 568, 2014/07

 Times Cited Count:1 Percentile:5.07(Chemistry, Multidisciplinary)

Journal Articles

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

 Times Cited Count:12 Percentile:45.92(Physics, Applied)

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$$d$$ 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 $$pi$$-$$d$$ hybridization and the effective spin transfer to the nitrogen atoms at the h-BN/Ni(111) interface.

Journal Articles

Controllable fabrication of amorphous Si layer by energetic cluster ion bombardment

Lavrentiev, V.*; Vorli$v{c}$ek, V.*; Dejneke, A.*; Chvostova, D.*; J$"a$ger, A.*; Vacik, J.*; Jastrabik, L.*; Naramoto, Hiroshi*; Narumi, Kazumasa

Vacuum, 98, p.49 - 55, 2013/12

 Times Cited Count:1 Percentile:4.47(Materials Science, Multidisciplinary)

Journal Articles

Spin orientation transition across the single-layer graphene/nickel thin film interface

Matsumoto, Yoshihiro; Entani, Shiro; Koide, Akihiro*; Otomo, Manabu; Avramov, P.; Naramoto, Hiroshi*; Amemiya, Kenta*; Fujikawa, Takashi*; Sakai, Seiji

Journal of Materials Chemistry C, 1(35), p.5533 - 5537, 2013/09

 Times Cited Count:32 Percentile:76.07(Materials Science, Multidisciplinary)

Journal Articles

High spin polarization at the Fe/C$$_{60}$$ interface in the Fe-doped C$$_{60}$$ film

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

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

 Times Cited Count:2 Percentile:9.67(Materials Science, Multidisciplinary)

Journal Articles

Cluster effect on damage accumulation in a Si crystal bombarded with 10-540-keV C$$_{60}$$ ions

Narumi, Kazumasa; Naramoto, Hiroshi*; Yamada, Keisuke; Chiba, Atsuya; Saito, Yuichi; Maeda, Yoshihito

JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 166, 2013/01

no abstracts in English

Journal Articles

Contact-induced spin polarization in graphene/$$h$$-BN/Ni nanocomposites

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

Journal of Applied Physics, 112(11), p.114303_1 - 114303_10, 2012/12

 Times Cited Count:18 Percentile:58.48(Physics, Applied)

Journal Articles

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

 Times Cited Count:38 Percentile:79.32(Chemistry, Physical)

Journal Articles

High hydrogen-adsorption-rate material based on graphane decorated with alkali metals

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

Physical Review B, 86(8), p.085435_1 - 085435_7, 2012/08

 Times Cited Count:54 Percentile:86.93(Materials Science, Multidisciplinary)

Journal Articles

Bias voltage dependence of tunneling magnetoresistance in granular C$$_{60}$$-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

 Times Cited Count:3 Percentile:14.19(Materials Science, Multidisciplinary)

Journal Articles

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

 Times Cited Count:21 Percentile:61.75(Physics, Applied)

${it In-situ}$ 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$$^{5}$$ 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$$_{2}$$ substrate are improved remarkably under the specific exposure conditions at which the growths of single- and bi-layer graphenes are completed.

Journal Articles

Energy dependence of nonlinear effects of sputtering yields of Si bombarded with 10-540-keV C$$_{60}$$ ions

Narumi, Kazumasa; Naramoto, Hiroshi*; Yamada, Keisuke; Saito, Yuichi; Chiba, Atsuya; Takahashi, Yasuyuki*; Maeda, Yoshihito

JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 155, 2012/01

no abstracts in English

Journal Articles

Ferromagnetic interlayer coupling in C$$_{60}$$-Co compound/Ni bilayer structure

Matsumoto, Yoshihiro; Sakai, Seiji; Entani, Shiro; Takagi, Yasumasa*; Nakagawa, Takeshi*; Naramoto, Hiroshi*; Avramov, P.; Yokoyama, Toshihiko*

Chemical Physics Letters, 511(1-3), p.68 - 72, 2011/07

 Times Cited Count:5 Percentile:15.93(Chemistry, Physical)

X-ray magnetic circular dichroism (XMCD) spectroscopy was employed to investigate the electronic and magnetic structures of the bilayers of a C$$_{60}$$-Co compound and Ni. A few -several nm thick C$$_{60}$$-Co compound layers on the Ni(111) surface are found to show intense XMCD signals attributed to the localized Co d-spins only with the remanent magnetization of Ni layer. It is suggested that the region of the C$$_{60}$$-Co compound within 3 nm from the interface is ferromagnetically coupled with Ni due to the indirect exchange interaction mediated by C$$_{60}$$, probably relevant to the interlayer charge transfer.

Journal Articles

${it Ab initio}$ 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

 Times Cited Count:25 Percentile:64.97(Chemistry, Physical)

Journal Articles

Effect of cotunneling and spin polarization on the large tunneling magnetoresistance effect in granular C$$_{60}$$-Co films

Sakai, Seiji; Mitani, Seiji*; Sugai, Isamu; Takanashi, Koki; Matsumoto, Yoshihiro; Entani, Shiro; Naramoto, Hiroshi*; Avramov, P.; Maeda, Yoshihito

Physical Review B, 83(17), p.174422_1 - 174422_6, 2011/05

 Times Cited Count:8 Percentile:35.07(Materials Science, Multidisciplinary)

333 (Records 1-20 displayed on this page)