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Miyagawa, Akihisa*; Hayashi, Naoki*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Miyazaki, Yasunori; Hasegawa, Kenta; Sano, Yuichi; Nakatani, Kiyoharu*
Analytical Sciences, 40(2), p.347 - 352, 2024/02
Times Cited Count：2 Percentile：14.77(Chemistry, Analytical)The Eu(III) distribution mechanism in single extractant-impregnated polymer-layered silica particle in a complex solution containing multiple lanthanide ions was investigated using fluorescence microspectroscopy. The rate-determining step was the reaction of Eu(III) with the two extractant molecules. The obtained mechanism and rate constants agreed with those of the single-ion distribution system, in which Eu(III) was distributed to the particles in the Eu(III) solution.
Miyagawa, Akihisa*; Hayashi, Naoki*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Miyazaki, Yasunori; Hasegawa, Kenta; Sano, Yuichi; Nakatani, Kiyoharu*
Bulletin of the Chemical Society of Japan, 96(9), p.1019 - 1025, 2023/09
Times Cited Count：4 Percentile：29.17(Chemistry, Multidisciplinary)In the present study, we have elucidated the mass transfer mechanism of Eu(III) and Sm(III) in the solution with these ions in single nitrilotriacetamide (NTA) extractant-impregnated polymer-coated silica particle. The rate-limiting process of mass transfer was the reaction process of ions with NTA molecules, in which the NO
ions were not involved, which was consistent with that obtained in single ion distribution system.
Terasawa, Tomoo; Matsunaga, Kazuya*; Hayashi, Naoki*; Ito, Takahiro*; Tanaka, Shinichiro*; Yasuda, Satoshi; Asaoka, Hidehito
Vacuum and Surface Science, 66(9), p.525 - 530, 2023/09
As Au (001) surfaces exhibit a quasi-one-dimensional corrugated structure, Hex-Au(001), its periodicity was predicted to change the electronic structure of graphene when graphene was grown on this surface. Furthermore, the hybridization between graphene and Au is known to introduce bandgap and spin polarization into graphene. Here, we report angle-resolved photoemission spectroscopy and density functional theory calculation of graphene on a Hex-Au(001) surface. A bandgap of 0.2 eV in the graphene Dirac cone was observed at the crossing point of the graphene Dirac cone and Au 6sp bands, indicating that the origin of the bandgap formation was the hybridization between the graphene Dirac cone and Au 6sp band. We discussed the hybridization mechanism and anticipated spin injection into the graphene Dirac cone.
Miyagawa, Akihisa*; Hayashi, Naoki*; Kuzure, Yoshiaki*; Takahashi, Takumi*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Miyazaki, Yasunori; Hasegawa, Kenta; Sano, Yuichi; et al.
Bulletin of the Chemical Society of Japan, 96(7), p.671 - 676, 2023/07
Times Cited Count：8 Percentile：53.09(Chemistry, Multidisciplinary)We investigated the distribution mechanism of Eu(III) in a single polymer-coated silica particle including nitrilotriacetamide (NTA) extractants known as HONTA and TOD2EHNTA. The present study provides a valuable approach for the evaluation and enhancement of the functionality of "single extractant-impregnated polymer-coated silica particle".
Terasawa, Tomoo; Matsunaga, Kazuya*; Hayashi, Naoki*; Ito, Takahiro*; Tanaka, Shinichiro*; Yasuda, Satoshi; Asaoka, Hidehito
Physical Review Materials (Internet), 7(1), p.014002_1 - 014002_10, 2023/01
Times Cited Count：10 Percentile：59.73(Materials Science, Multidisciplinary)Au(001) surfaces exhibit a complex reconstructed structure [Hex-Au(001)] comprising a hexagonal surface and square bulk lattices, yielding a quasi-one-dimensional corrugated surface. When graphene was grown on this surface, the periodicity of the corrugated surface was predicted to change the electronic structure of graphene, forming bandgaps and new Dirac points. Furthermore, the graphene-Au interface is promising for bandgap generation and spin injection due to band hybridization. Here, we report the angle-resolved photoemission spectroscopy and density functional calculation of graphene on a Hex-Au(001) surface. The crossing point of the original and replica graphene 
bands showed no bandgap, suggesting that the one-dimensional potential was too small to modify the electronic structure. A bandgap of 0.2 eV was observed at the crossing point of the graphene and Au 
bands, indicating that the bandgap is generated using hybridization of the graphene and Au bands. We discussed the hybridization mechanism and concluded that the R30 configuration between graphene and Au and an isolated electronic structure of Au are essential for effective hybridization between graphene and Au. We anticipate that hybridization between graphene and Au would result in spin injection into graphene.
Terasawa, Tomoo; Yasuda, Satoshi; Matsunaga, Kazuya*; Hayashi, Naoki*; Tanaka, Shinichiro*; Norimatsu, Wataru*; Ito, Takahiro*; Machida, Shinichi*; Asaoka, Hidehito
no journal, ,
Graphene grown on Hex-Au(001) substrate shows an energy gap in its -band. Previous reports speculated that the periodic potential of Hex-Au(001) resulted in the energy gap formation in the -band of graphene. In the present study, we found by angle-resolved photoemission spectroscopy that the hybridyzation of sp-band of Hex-Au(001) and -band of graphene created the energy gap in the -band of graphene.
Hayashi, Naoki*; Miyagawa, Akihisa*; Nagatomo, Shigenori*; Nakatani, Kiyoharu*; Sato, Kiyomori*; Arai, Tsuyoshi*; Ambai, Hiromu; Hasegawa, Kenta; Watanabe, So; Sano, Yuichi
no journal, ,
The fluorescence of lanthanide ions within a single extractant-impregnated silica particle was obtained using a microspectrometer to evaluate their distribution behavior within the particle.
Terasawa, Tomoo; Matsunaga, Kazuya*; Hayashi, Naoki*; Ito, Takahiro*; Tanaka, Shinichiro*; Yasuda, Satoshi; Asaoka, Hidehito
no journal, ,
As a Hex-Au(001) surface shows one-dimensional corrugation and is chemically inert, it has been employed to study the effect of one-dimensional potential on graphene. Such potential has been expected to make the band structure of graphene anisotropic, which shows the mini-gap at the zone boundary across the potential and the high group velocity along the potential. However, the bandgap in the graphene on Hex-Au(001) was only indirectly suggested by scanning tunneling spectroscopy. Here, we report the band structure of graphene on Hex-Au(001) substrates using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculation. The ARPES image shows the bandgap in the graphene band close to the Au 6sp band. The DFT calculated band structure shows the bandgap not at the crossing point of the graphene bands but that of graphene and Au 6sp bands. We thus conclude that the bandgap originates from the hybridization between graphene and Au. This hybridization is similar to that observed in the graphene and Au interface on the SiC substrate. We expect that the hybridization between graphene and Au is essential as the Rashba splitting of 100 meV was observed around the gap.
Terasawa, Tomoo; Yasuda, Satoshi; Hayashi, Naoki*; Norimatsu, Wataru*; Ito, Takahiro*; Machida, Shinichi*; Yano, Masahiro; Saiki, Koichiro*; Asaoka, Hidehito
no journal, ,
We report the band structure of graphene grown on hex-Au(001) using angle resolved photoemission spectroscopy (ARPES). We prepared graphene on hex-Au(001) by chemical vapor deposition and took ARPES image of the sample at AichiSR BL7U. The linear graphene band shows the intensity reduction at the binding energy of approximately 0.9 eV, indicating the modification of band structure of graphene by quasi-one dimensional potential of the hex-Au(001) reconstructed surface.
Inose, Kenta; Ouchi, Masayuki; Tobita, Ryuto; Aoki, Kenji; Asada, Naoki; Kusaka, Shota; Morita, Kazuki; Oyama, Koichi; Sumi, Hirotaka; Nakabayashi, Hiroki
no journal, ,
At the Tokai Reprocessing Plant, safety measures have been taken to maintain important safety functions in the High Active Liquid Waste Storage Facility (HAW) and Tokai Vitrification Facility (TVF), which handle high active liquid waste, in accordance with new regulatory requirements and assuming the occurrence of internal events such as fire and flooding. Fire prevention measures were taken to prevent the occurrence of fires, detect and extinguish fires, and mitigate the impact of fires. Flooding measures were taken to effects of submersion, water coverage, and steam due to flooding. In addition to measures against internal hazards, measures for external hazards and accident response measures have been completed, improving the safety of the HAW and TVF.
Terasawa, Tomoo; Yasuda, Satoshi; Hayashi, Naoki*; Norimatsu, Wataru*; Ito, Takahiro*; Machida, Shinichi*; Yano, Masahiro; Saiki, Koichiro*; Asaoka, Hidehito
no journal, ,
Terasawa, Tomoo; Yasuda, Satoshi; Hayashi, Naoki*; Norimatsu, Wataru*; Ito, Takahiro*; Machida, Shinichi*; Asaoka, Hidehito
no journal, ,
Graphene shows absorptivity and emissivity of 2.3% independent from the wavelength, however, the wavelength selectivity of the optical properties is required for device applications. Here we report the observation of the electronic band structure and thermal radiation of graphene grown on hex-Au(001) structure. The thermal radiation of graphene grown on hex-Au(001) was decreased in the optical microscopy which observed the light with the wavelength of 700-900 nm. The same sample showed the modified band structure observed by angle resolved photoemission spectroscopy. We will discuss the relation between the thermal radiation and band structure of graphene on Au substrates.
Terasawa, Tomoo; Yasuda, Satoshi; Hayashi, Naoki*; Norimatsu, Wataru*; Ito, Takahiro*; Machida, Shinichi*; Yano, Masahiro; Saiki, Koichiro*; Asaoka, Hidehito
no journal, ,
Terasawa, Tomoo; Yasuda, Satoshi; Hayashi, Naoki*; Norimatsu, Wataru*; Ito, Takahiro*; Machida, Shinichi*; Asaoka, Hidehito
no journal, ,
no abstracts in English
