Nakajima, Atsushi

写真a

Affiliation

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

Position

Professor

External Links
Page Top ▲

Career 【 Display / hide 】

  • 1989.04
    -
    1994.03

    大学助手(理工学部化学科)

  • 1994.04
    -
    1997.03

    大学専任講師(理工学部化学科)

  • 1997.04
    -
    2001.03

    大学助教授(理工学部化学科)

  • 2001.04
    -
    Present

    大学教授(理工学部化学科)

  • 2001.04
    -
    Present

    大学院理工学研究科委員

display all >>

Page Top ▲

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

Page Top ▲

Academic Degrees 【 Display / hide 】

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

Page Top ▲

Matters concerning Career Achievements 【 Display / hide 】

  • 2001.10
    -
    2007.09

    大学学生総合センター委員(矢上支部)

  • 2006.04
    -
    2008.03

    大学院理工学研究科専修主任(機能デザイン科学)

  • 2008.04
    -
    2009.09

    大学理工学部企画室会議委員

  • 2009.04
    -
    2011.03

    大学理工学部学習指導副主任(化学科)

  • 2010.04
    -
    2013.09

    大学理工学部企画室会議委員

display all >>

Page Top ▲
 

Research Areas 【 Display / hide 】

  • Nanotechnology/Materials / Fundamental physical chemistry (Physical Chemistry)

Page Top ▲

Research Themes 【 Display / hide 】

  • Nanocluster Assembled Material Science, 

    2009
    -
    2015

  • 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」, 

    2002
    -
    2007

    　View Summary

    本研究では、多元的な化学組成の制御を通じて電子構造をデザインした複合ナノクラスターを創成し、このクラスターを機能単位とする二次元系ナノクラスター物質を、ナノメートルオーダーで周期的にデザイン制御した固体表面上への選択的なソフトランディングによって構築します。ナノデザイン制御されたクラスター物質での電

Page Top ▲
 

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

    　View Summary

    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

    　View Summary

    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

display all >>

Page Top ▲

Papers 【 Display / hide 】

  • Tailoring Superatomic Stability with Transition Metals in Silicon Cages: Shrinking to M@Si<inf>15</inf> (M = Re, Os, Ir)

    Ichikawa T., Terasaka K., Sasaki A., Nakajima A.

    Journal of Physical Chemistry Letters 15 ( 46 ) 11678 - 11686 2024.11

    　View Summary

    The design of materials with intriguing electronic properties is crucial for advancing nanoscale technologies, where precise control over atomic structure and electronic behavior is essential. Metal-encapsulating silicon cage superatoms (SAs) provide a new paradigm for molecular-scale material design, allowing fine-tuning of both structure and electronic characteristics. The formation of superatoms mimicking halogens, noble gases, and alkali metals has been well-studied, particularly with M@Si16, where early transition metals from groups 3 to 5 stabilize within a Si16 cage, achieving a 68-electron configuration. For late transition metals with excess electrons, a Si15 cage offers enhanced stability by fulfilling the 68-electron rule with one fewer Si atom. This research synthesizes Si15 cage-SAs with rhenium (Re) from group 7 and iridium (Ir) from group 9 on p-type and n-type organic substrates. The stability of Re@Si15 and Ir@Si15 is evaluated via oxidative reactivity with X-ray photoelectron spectroscopy and theoretical calculations, including osmium (Os) from group 8. Re@Si15-, Os@Si150, and Ir@Si15+ exhibit superatomic behaviors similar to halogens, noble gases, and alkali metals due to the 68-electron shell closure. Among them, Re@Si15- on p-type organic substrates shows superior electronic and geometric properties. These findings advance our understanding of M@Sin systems for transition metals, addressing longstanding questions about their properties at n = 15 and 16.

  • Photoemission spectroscopy and microscopy for Ta@Si<inf>16</inf> superatoms and their assembled layers

    Shibuta M., Ohta T., Kamoshida T., Yamagiwa K., Tsunoyama H., Inoue T., Masubuchi T., Nakajima A.

    Nanoscale 16 ( 47 ) 21837 - 21846 2024.10

    ISSN  20403364

    　View Summary

    Superatoms (SAs) with specific compositions have the potential to significantly advance the field of nanomaterials science, leading to next-generation nanoscale functionalities. In this study, we fabricated assembled layers with tantalum metal-atom encapsulating silicon cage (Ta@Si16) SAs on an organic C60 substrate through deposition, and we characterized their electronic and optical properties by photoelectron spectroscopy and microscopy. The alkaline nature of Ta@Si16 SAs reveals their electronic behaviors, such as charge transfer and electromagnetic near-field sensing, through two-photon photoemission (2PPE) spectroscopy and microscopy with a femtosecond laser. The evolution of the work function for Ta@Si16 SAs on C60, observed by 2PPE spectroscopy, demonstrates charge transfer complexation between the topmost C60 layer and the first Ta@Si16 layer, consistent with the electron-donating alkaline characteristics of Ta@Si16 SAs. Specifically, a small amount of Ta@Si16 SA deposition leads to a dramatic increase in 2PPE intensity, attributable to electromagnetic near-field enhancements, suggesting applications as sensitizers for nonlinear imaging in photoemission microscopy. For the assembled Ta@Si16 SA layers, a plasmonic response of hνp = 17.9 eV is spectroscopically identified, including their valence and conduction band structures, and the plasmonic energetics are discussed in the context of metal doping in bulk silicon.

  • Geometric and Electronic Properties of P Atom-Doped Al Nanoclusters: Alkaline-like Superatom of P@Al<inf>12</inf>

    Akutsu M., Koyasu K., Miyajima K., Mitsui M., Inoue T., Nakajima A.

    Journal of Physical Chemistry A 128 ( 32 ) 6648 - 6657 2024.08

    ISSN  10895639

    　View Summary

    The geometric and electronic characteristics of phosphorus-atom doped aluminum nanoclusters, AlnPm (n = 7-17, m = 1 and 2), were investigated through a combination of experiments and theoretical calculations. The size dependences of the ionization energy (Ei) for AlnPm NCs exhibit a local minimum of 5.37 eV at Al12P1, attributed to an endohedral P@Al12 superatom (SA). This SA originates from an excess electron toward the 2P shell closing (40e), coexisting with an exohedral isomer featuring a vertex P atom. The stability of the endohedral P@Al12 is further enhanced in its cationic state compared to the exohedral isomer, when complexed with a fluorine (F) atom, forming an SA salt denoted as P@Al12+F- with an elevated Ei ranging from 6.42 to 7.90 eV. In contrast, for the anionic Al12P1-, the exohedral form is found to be more stable than the endohedral one using anion photoelectron spectroscopy and calculations. The geometric and electronic robustness of neutral P@Al12 SAs against electron donation and acceptance is discussed in comparison to rare-gas-like Si@Al12 SAs.

  • Extended X-ray Absorption Fine Structure (EXAFS) Measurements on Alkali Metal Superatoms of Ta-Atom-Encapsulated Si<inf>16</inf> Cage

    Inoue T., Ina T., Masai H., Kondo N., Matsui F., Kinoshita T., Nakajima A.

    Journal of Physical Chemistry Letters (American Chemical Society)  15 ( 20 ) 5376 - 5381 2024.06

    Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted

    　View Summary

    The silicon cage nanoclusters encapsulating a tantalum atom, termed Ta@Si16, exhibit characteristics of alkali metal “superatoms (SAs)”. Despite this conceptual framework, the precise structures of Ta@Si16 and Ta@Si16+ remain unclear in quantum calculations due to three energetically close structural isomers: C3v, Td, and D4d structures. To identify the geometrical structure of Ta@Si16 SAs, structural analysis was conducted using extended X-ray absorption fine structure (EXAFS) with a high-intensity monochromatic X-ray source, keeping anaerobic conditions. Focusing on “superordered” films, which constitute amorphous thin films composed solely of Ta@Si16 SAs, this analysis preserved locally ordered structures. Spectral comparisons between experimental and simulated Ta L3-edge EXAFS unveil that Ta@Si16 SAs on a substrate adopt a C3v-derived structure, while Si K-edge EXAFS introduces spectral ambiguity in structural identifications, attributed to both intracluster and intercluster scatterings. These findings underscore the significance of locally ordered structure analyses in understanding and characterizing novel nanoscale materials.

  • Localized surface plasmon resonances of size-selected large silver nanoclusters (n = 70-100) soft-landed on a C<inf>60</inf> organic substrate

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

    Physical Chemistry Chemical Physics 26 ( 23 ) 16597 - 16602 2024.05

    ISSN  14639076

    　View Summary

    Silver nanoclusters (Agn NCs) exhibit a remarkable optical property known as localized surface plasmon resonance (LSPR) in the visible to ultraviolet wavelengths. In this study, we address the size gap in LSPR responses between small NCs and nano-islands by synthesizing large Agn NCs with a countable number of atoms (n = 70-100) using a magnetron sputtering method, which were precisely size-selected and soft-landed onto substrates. The monodispersed Agn NCs were immobilized on a pre-decorated substrate with fullerene (C60) molecules, and their LSPR behaviors were characterized using two-photon photoemission (2PPE) spectroscopy. Due to the distinct polarization selectivity of incident light associated with LSPR, the intensity ratio between p- and s-polarized lights (Ip/Is) in 2PPE spectroscopy serves as a reliable indicator of LSPR and its structural correlations. From n = 70 to 100, the Ip/Is value gradually decreases as the cluster size increases. This decrease is attributed to the enhancement of s-polarized light (Is), indicating that large Agn NCs on a C60 substrate undergo a deformation from spherical to flattened geometries, particularly above approximately n = 55.

display all >>

Page Top ▲

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

Page Top ▲

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

    Article, review, commentary, editorial, etc. (scientific journal), Joint Work,  ISSN  1882-2398

    　View Summary

    <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>

Page Top ▲

Presentations 【 Display / hide 】

  • Monodispersed Immobilization and Island Formation of M@Si16 Superatom

    NAKAJIMA ATSUSHI

    The Cluster Surface Interactions 2016 Workshop (Argonne National Laboratory) , 

    2016.06
    , 

    Oral presentation (invited, special)

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

    NAKAJIMA ATSUSHI

    Symposium on Size Selected Clusters (S3C) 2016 (Davos, Switzerland) , 

    2016.03
    , 

    Oral presentation (keynote)

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

    NAKAJIMA ATSUSHI

    Pacifichem 2015 (Honolulu, Hawaii, USA) , 

    2015.12
    , 

    Oral presentation (invited, special)

  • Formation of binary superatom nanocluster monolayer

    NAKAJIMA ATSUSHI

    XXIV International Materials Research Congress (IMRC) on Clusters & Nanostructures (Cancun, Mexico) , 

    2015.08
    , 

    Oral presentation (invited, special)

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

    NAKAJIMA ATSUSHI

    2015 Gordon Research Conference (GRC) “Clusters and Cluster Assembled Materials” (Girona, Spain) , 

    2015.07
    , 

    Oral presentation (invited, special)

display all >>

Page Top ▲

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

    2002.10
    -
    2007.09

    Keio University, Kobe University, Osaka University, Hiroshima University, University of Chicago, Argonne National Laboratory, -, Research grant, No Setting

  • Development of Sub-nanosized Aggregates Having Novel Optical Properties

    1997.07
    -
    2003.03

    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, No Setting

    　View Summary

    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

    1999.04
    -
    2004.03

    Keio University, Special Coordination Funds for the promotion of Science and Technology, Research grant, No Setting

  • 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

    2003.04
    -
    2006.03

    慶應義塾大学, Grant-in-Aid for Scientific Research, Research grant, No Setting

  • 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

    2001.04
    -
    2003.03

    Grant-in-Aid for Scientific Research, Research grant, No Setting

display all >>

Page Top ▲

Intellectual Property Rights, etc. 【 Display / hide 】

  • ナノクラスター生成装置

    Date applied： 2013－112995  2013.05 

    Patent, Joint

  • 多重レーザー照射による液滴試料の粉砕法

    Date applied： 2012-162131  2012.07 

    Patent, Joint

  • “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”

    Date applied： 2012-0989620  2012.04 

    Patent, Joint

  • 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

    Date applied： 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

    Date applied： 2016-033117   

    Patent, Joint

display all >>

Page Top ▲

Awards 【 Display / hide 】

  • 令和5年度　文部科学大臣表彰　科学技術賞　研究部門

    2023.04, 文部科学省, 複合ナノクラスター精密担持法によるナノ機能表面化学の研究

    Type of Award： Other

  • Humboldt Research Award

    2020.05, アレクサンダー・フンボルト財団

    Type of Award： International academic award (Japan or overseas)

  • 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： Award from Japanese society, conference, symposium, etc.

  • 田中貴金属研究財団 シルバー賞

    2017.03

    Type of Award： Award from publisher, newspaper, foundation, etc.

  • 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： Award from Japanese society, conference, symposium, etc.

display all >>

Page Top ▲
 

Courses Taught 【 Display / hide 】

  • STATISTICAL THERMODYNAMICS (BASIC PHYSICAL CHEMISTRY 1)

    2024

  • STATISTICAL THERMODYNAMICS

    2024

  • STATISTICAL CHEMICAL THERMODYNAMICS EXERCISE

    2024

  • SEMINAR IN CHEMISTRY

    2024

  • QUANTUM STATISTICAL CHEMISTRY (PHYSICAL CHEMISTRY 2)

    2024

display all >>

Page Top ▲
 

Memberships in Academic Societies 【 Display / hide 】

  • 分子科学会, 

    2004.09
    -
    Present

  • ナノ学会, 

    2004.05
    -
    2020.03

  • 日本物理学会, 

    1984.03
    -
    Present

  • 日本化学会, 

    1983.10
    -
    Present
Page Top ▲

Committee Experiences 【 Display / hide 】

  • 2020.06
    -
    Present

    理事, 日本化学会

  • 2008.09
    -
    2010.08

    会長, 分子科学会

  • 2006.08
    -
    Present

    連携会員, 日本学術会議

  • 2004.09
    -
    2006.08

    Committee Chair, 分子科学研究会

  • 2004.05
    -
    2020.03

    Director, ナノ学会

display all >>

Page Top ▲