Nakajima, Atsushi



Faculty of Science and Technology, Department of Chemistry (Yagami)



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Career 【 Display / hide

  • 1989.04


  • 1994.04


  • 1997.04


  • 1999.04

    東京都立大学大学院 非常勤講師

  • 2001.04


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Academic Background 【 Display / hide

  • 1984.03

    The University of Tokyo, Faculty of Science, 化学科

    University, Graduated

  • 1986.03

    The University of Tokyo, Graduate School, Division of Natural Science, 化学専攻

    Graduate School, Completed, Master's course

  • 1989.03

    The University of Tokyo, Graduate School, Division of Natural Science

    Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide

  • Dr. Sc., The University of Tokyo, Coursework, 1989.03


Research Areas 【 Display / hide

  • Basic chemistry (Physical Chemistry)

Research Themes 【 Display / hide

  • Nanocluster Assembled Material Science, 


  • 科学技術振興機構 戦略創造プログラム(CREST) 研究課題「次世代光磁気材料を指向したナノデザイン制御」, 


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Books 【 Display / hide

  • Electronic properties of transition metal-benzene sandwich clusters

    Masubuchi T., Nakajima A., Theoretical Chemistry for Advanced Nanomaterials: Functional Analysis by Computation and Experiment, 2020.01

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    Organometallic clusters composed of transition metal atoms and benzene molecules have been topics of great interest from both fundamental and technological points of view. In this chapter, we review the progress in the physical chemistry of transition metal-benzene clusters. The intrinsic properties of transition metal-benzene clusters as a function of cluster size are investigated by gasphase experiments, often in combination with quantum chemical calculations. In particular, vanadium-benzene clusters denoted VnBzm, showing magic numbers at m = n + 1, n, and n – 1, are characterized to possess multiple-decker sandwich structures, where vanadium atoms and benzene molecules are alternately piled up. Moreover, the discovery of such multiple-decker formation is a cornerstone in bottom-up approaches of molecular magnetism. The interplay of mass spectrometry, laser spectroscopies, and density functional calculations reveals that multiple-decker VnBzm clusters exhibit monotonic increase in magnetic moment with the number of layers. Anion photoelectron spectroscopic studies allow direct observations of the geometric and electronic structures of sandwich clusters and their anions. Major progress in this direction includes the recent characterization of tilted multipledecker sandwich cluster anions composed of manganese atoms and benzene molecules. The sandwich clusters with high-spin characteristics will hopefully be exploited as building blocks in advanced electronic and magnetic nanomaterials via controlled assembly.

  • Formation of superatom monolayer using nanocluster ion source based on high-power impulse magnetron sputtering

    Nakajima A., Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry, 2018.01

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    The assembled monolayer of superatomic nanocluster ions synthesized in the gas phase is formed with monodispersive immobilization of Ta atom-encapsulated Si16 cage superatom (Ta@Si16) with an intensive ion source based on high-power impulse magnetron sputtering (HiPIMS). Scanning tunneling microscopy and spectroscopy have demonstrated that superatom cations of Ta@Si16+ can be densely immobilized on C60-terminated surfaces while retaining their cage shape by forming charge transfer (CT) complexes ((Ta@Si16)+C60-) on the surfaces. Its chemical states of Ta@Si16 deposited on an electron acceptable C60 fullerene film were evaluated by X-ray photoelectron spectroscopies (XPS). XPS results for Si, Ta, and C elements showed that Ta@Si16 combines with a single C60 molecule to form (Ta@Si16)+C60-. The high thermal and chemical robustness of the superatomic CT complex has been revealed by the XPS measurements conducted before and after heat treatment and oxygen exposure. The formation of robust superatom monolayer with HiPIMS demonstrates that the superatoms including metal-encapsulating silicon cage superatoms have a promising potential to be utilized for building blocks of novel functional nanomaterials.

  • 最新 実用真空技術総覧 クラスタービーム生成

    NAKAJIMA ATSUSHI, ㈱産業技術サービスセンター, 2017

  • シリコンフラーレン

    NAKAJIMA ATSUSHI, 慶應義塾機関紙 三田評論, 2014

  • 現代界面コロイド科学の事典 10.4節「金属ナノクラスター」

    NAKAJIMA ATSUSHI, 丸善, 2010

    Scope: 240-241

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Papers 【 Display / hide

  • Electrical Conduction of Superatom Thin Films Composed of Group-V-Metal-Encapsulating Silicon-Cage Nanoclusters

    Takaho Yokoyama, Tatsuya Chiba, Naoyuki Hirata, Masahiro Shibuta, and Atsushi Nakajima

    Journal of Physical Chemistry C (ACS)  125 ( 33 ) 18420 - 18428 2021.08

    Research paper (scientific journal), Joint Work, Accepted

  • Confined Hot Electron Relaxation at the Molecular Heterointerface of the Size-Selected Plasmonic Noble Metal Nanocluster and Layered C<inf>60</inf>

    Shibuta M., Yamamoto K., Ohta T., Inoue T., Mizoguchi K., Nakaya M., Eguchi T., Nakajima A.

    ACS Nano (ACS)  15 ( 1 ) 1199 - 1209 2021.01

    ISSN  19360851

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    The plasmonic response of metallic nanostructures plays a key role in amplifying photocatalytic and photoelectric conversion. Since the plasmonic behavior of noble metal nanoparticles is known to generate energetic charge carriers such as hot electrons, it is expected that the hot electrons can enhance conversion efficiency if they are transferred into a neighboring molecule or semiconductor. However, the method of transferring the energized charge carriers from the plasmonically generated hot electrons to the neighboring species remains controversial. Herein, we fabricated a molecularly well-defined heterointerface between the size-selected plasmonic noble-metal nanoclusters (NCs) of Agn (n = 3-55)/Aun (n = 21) and the organic C60 film to investigate hot electron generation and relaxation dynamics using time-resolved two-photon photoemission (2PPE) spectroscopy. By tuning the NC size and the polarization of the femtosecond excitation photons, the plasmonic behavior is characterized by 2PPE intensity enhancement by 10-100 times magnitude, which emerge at n ≥ 9 for Agn NCs. The 2PPE spectra exhibit contributions from low-energy electrons forming coherent plasmonic currents and hot electrons with an excitation energy up to photon energy owing to two-photon excitation of an occupied state of the Agn NC below the Fermi level. The time-resolved pump-probe measurements demonstrate that plasmon dephasing generates hot electrons which undergo electron-electron scattering. However, no photoemission occurs via the charge transfer state forming Agn+C60- located in the vicinity of the Fermi level. Thus, this study reveals the mechanism of ultrafast confined hot electron relaxation within plasmonic Agn NCs at the molecular heterointerface.

  • Interfacial oxidation of TA-encapsulating Si<inf>16</inf> cage superatoms (Ta@Si<inf>16</inf>) on strontium titanate substrates

    Nakajima A., Shibuta M., Takano R.

    Journal of Physical Chemistry C (ACS)  124 ( 51 ) 28108 - 28115 2020.12

    ISSN  19327447

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    Nanocluster immobilization on an oxide surface is fundamentally important for forming nanocluster-assembled layered materials. We fabricated multilayered superatom films made of tantalum-encapsulating Si16 cage nanocluster (Ta@Si16) on a strontium titanate substrate (SrTiO3; STO) by the soft landing of size-selective Ta@Si16. X-ray photoelectron spectroscopy (XPS) revealed that Ta@Si16 survived at the interfacial oxide layer without oxidizing the central Ta atom, and pure Ta@ Si16 layers were formed successively on the modified Ta@Si16/STO interfacial layer. The Ta@Si16 superatoms in the multilayered Ta@Si16 showed high chemical robustness against O2 exposure, although the topmost Ta@Si16 surface layer, including the central Ta atom, completely oxidized in ambient O2 over several days. XPS depth analysis showed that Ta@Si16 oxide formation was limited only at the topmost single layer, revealing that the middle Ta@Si16 layers sandwiched between the top and bottom were protected by the formation of interfacial oxides.

  • Occupied and Unoccupied Levels of Half-Fluorinated and Perfluorinated Rubrene Thin Films Probed by One- And Two-Photon Photoemission

    Inoue T., Shibuta M., Suzuki T., Nakajima A.

    Journal of Physical Chemistry C (ACS)  124 ( 23 ) 12409 - 12416 2020.06

    ISSN  19327447

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    © 2020 American Chemical Society. We measured occupied and unoccupied energy levels of half-fluorinated and perfluorinated rubrenes (C42F14H14, F14-RUB, and C42F28, PF-RUB) thin films prepared on a highly oriented pyrolytic graphite substrate by a combination of one- and two-photon photoemission spectroscopies. It is revealed that the energy levels near the Fermi level (EF) decrease when the fluorination degree increases, where the energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are located at EF - 1.83 eV and EF + 0.9 eV for F14-RUB and EF - 2.51 eV and EF + 0.6 eV for PF-RUB, respectively. The HOMO-LUMO gaps corresponding to the energy for the creation of free photocarriers in molecular films - known as "transport gaps"- are evaluated by 2.7 eV for F14-RUB and 3.1 eV for PF-RUB.

  • Visualization of Surface Plasmons Propagating at the Buried Organic/Metal Interface with Silver Nanocluster Sensitizers

    Yamagiwa K., Shibuta M., Nakajima A.

    ACS Nano (ACS)  14 ( 2 ) 2044 - 2052 2020.02

    ISSN  19360851

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    © 2020 American Chemical Society. Visualization of surface plasmon polariton (SPP) propagation at dielectric/metal interfaces is indispensable in providing opportunities for the precise designing and controlling of the functionalities of future plasmonic nanodevices. Here, we report the visualization of SPPs propagating along the buried organic/metal interface of fullerene (C60)/Au(111), through dual-colored two-photon photoemission electron microscopy (2P-PEEM) which precisely visualizes the SPP propagation of plasmonic metal nanostructures. Although SPPs excited by near-infrared photons at the few monolayer C60/Au(111) interface are clearly visualized as interference beat patterns between the SPPs and incident light, faithfully reflecting SPP properties modulated by the overlayer, photoemission signals are suppressed for thicker C60 films, due to less valence electrons participating in 2P-photoemission processes. With the use of silver (Agn (n = 21 and 55)) nanoclusters, which exhibit enhancement of overall photoemission intensities due to localized surface plasmons functioning as SPP sensitizers, it is revealed that the 2P-PEEM is applicable to the imaging of SPPs for thick C60/Au(111) interfaces, where SPP properties are hardly modulated by the added small amount (∼0.1 monolayer) of Agn sensitizers.

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Papers, etc., Registered in KOARA 【 Display / hide

Reviews, Commentaries, etc. 【 Display / hide

  • Fabrication method for nanocluster superatoms with high-power impulse magnetron sputtering

    Tsunoyama Hironori, Tona Masahide, Tsukamoto Keizo, Nakajima Atsushi

    Journal of the Vacuum Society of Japan 60 ( 9 ) 352 - 361 2017

    Introduction and explanation (scientific journal), Joint Work,  ISSN  1882-2398

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    <p>Intensive ion source for single-size nanoclusters was developed on the basis of high-power impulse magnetron sputtering (HiPIMS) technique combined with a low-pressure, low-temperature gas flow reactor. The nanocluster source exhibits superior characteristics originating from pulsed, high-power sputtering compared to conventional direct-current sputtering; (1) enhanced ion intensities, (2) fascicle tuning of nanocluster sizes, and (3) enhanced selectivity of stable, magic nanoclusters. The metallic (silver, platinum, and palladium) and binary (transition-metal and silicon) nanocluster ions in the size range of several to one hundred atoms can be generated with ion current of 100 pA to 10 nA (108 to 1011 nanoclusters/sec). The growth mechanism of nanoclusters in the source was also explained by the nucleation theory.</p>

Presentations 【 Display / hide

  • Monodispersed Immobilization and Island Formation of M@Si16 Superatom


    The Cluster Surface Interactions 2016 Workshop (Argonne National Laboratory) , 2016.06, Oral Presentation(guest/special)

  • Alkali-Like Binary Superatom of a Ta-Encapsulating Si16 Cage


    Symposium on Size Selected Clusters (S3C) 2016 (Davos, Switzerland) , 2016.03, Oral Presentation(key)

  • Nanocluster superatom formation using ion source based on high-power impulse magnetron sputtering


    Pacifichem 2015 (Honolulu, Hawaii, USA) , 2015.12, Oral Presentation(guest/special)

  • Formation of binary superatom nanocluster monolayer


    XXIV International Materials Research Congress (IMRC) on Clusters & Nanostructures (Cancun, Mexico) , 2015.08, Oral Presentation(guest/special)

  • Formation of Superatom Monolayer Using Nanocluster Ion Source Based on High-Power Impulse Magnetron Sputtering


    2015 Gordon Research Conference (GRC) “Clusters and Cluster Assembled Materials” (Girona, Spain) , 2015.07, Oral Presentation(guest/special)

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • 次世代光磁気材料を指向したナノデザイン制御


    Keio University, Kobe University, Osaka University, Hiroshima University, University of Chicago, Argonne National Laboratory, -, Research grant

  • Development of Sub-nanosized Aggregates Having Novel Optical Properties


    Keio University, Kobe University, Tohoku University, Institute for Molecular Science, “Research for the Future (RFTF)” of the Japan Society for the Promotion of Science, Research grant

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    We have successfully established several new methodologies to generate sub-nanosized aggregates having novel optical properties, and revealed fundamental properties of their electronic and geometrical structures as well as molecular aggregates bridging between gas and liquid/solid phases. New areas of “gas-phase organometallic chemistry” have been developed to create and to design new optoelectronic materials with our proposed soft-landing method.

  • Study of Magnetic Bottle Electron Spectrometer and Their Application


    Keio University, Special Coordination Funds for the promotion of Science and Technology, Research grant

  • ナノ生体触媒の創成を指向したニトロゲナーゼ酵素の鉄-硫黄活性中心のデザイン制御


    慶應義塾大学, Grant-in-Aid for Scientific Research, Research grant

  • 気相多元系合金クラスターの基板担持による触媒機能と電子物性の研究


    Grant-in-Aid for Scientific Research, Research grant

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Intellectual Property Rights, etc. 【 Display / hide

  • ナノクラスター生成装置

    Application No.: 2013-112995  2013.05 

    Patent, Joint, National application

  • 多重レーザー照射による液滴試料の粉砕法

    Application No.: 2012-162131  2012.07 

    Patent, Joint, National application

  • “マイクロミキサー、マイクロミキサーエレメント及びその製造方法”

    Application No.: 2012-0989620  2012.04 

    Patent, Joint, National application

  • ナノクラスター分散液、ナノクラスター膜、ナノクラスター分散体の製造方法およびナノクラスター分散液の製造装置

    Application No.: 2015-160680   

    Patent, Joint

  • マイクロミキサー、マイクロミキサーエレメントおよびその製造方法

    Application No.: 2016-033117   

    Patent, Joint

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Awards 【 Display / hide

  • Humboldt Research Award

    2020.05, アレクサンダー・フンボルト財団

    Type of Award: International Academic Awards

  • 分子科学会賞

    2018.08, 分子科学会, 複合ナノクラスター科学の開拓-気相化学からナノ機能表面化学へ

    Type of Award: Awards of National Conference, Council and Symposium

  • 田中貴金属研究財団 シルバー賞


    Type of Award: Awards of Publisher, Newspaper Company and Foundation

  • The Chemical Society of Japan Award for Creative Work for 2008

    NAKAJIMA ATSUSHI, 2009.03, 社団法人 日本化学会, 複合クラスターを用いたナノスケール物質群の創製とその電子物性の解明

    Type of Award: Awards of National Conference, Council and Symposium

  • Chemical Physics Letters Most Cited Paper 2003-2007 Award

    2008.10, Elsevier

    Type of Award: International Academic Awards

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Courses Taught 【 Display / hide











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Memberships in Academic Societies 【 Display / hide

  • 分子科学会, 

  • ナノ学会, 

  • 日本物理学会, 

  • 日本化学会, 


Committee Experiences 【 Display / hide

  • 2020.06

    理事, 日本化学会

  • 2008.09

    会長, 分子科学会

  • 2006.08

    連携会員, 日本学術会議

  • 2004.09

    Committee Chair, 分子科学研究会

  • 2004.05

    Director, ナノ学会

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