Details of a Researcher - Nakajima, Atsushi

Nakajima, Atsushi

写真a

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

Position: Professor

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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)
1999.04

-

2000.03

東京都立大学大学院　非常勤講師
2001.04

-

Present

大学院理工学研究科委員

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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

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Academic Degrees 【 Display / hide 】

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

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Research Areas 【 Display / hide 】

Nanotechnology/Materials / Fundamental physical chemistry (Physical Chemistry)

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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

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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

　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

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Papers 【 Display / hide 】

Al₁₃^- and B@Al₁₂^- superatoms on a molecularly decorated substrate

Masahiro Shibuta, Tomoya Inoue, Toshiaki Kamoshida, Toyoaki Eguchi, and Atsushi Nakajima*

Nature Communications （Springer Nature) 13 1336 2022.03

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted
Size-Dependent Oxidative Stability of Silicon Nanoclusters Mixed with a Tantalum-Atom

Masahiro Shibuta,　Maximilian Huber, Toshiaki Kamoshida, Kazuya Terasaka, Miho Hatanaka,　Gereon Niedner-Schatteburg, and Atsushi Nakajima

J. Phys. Chem. C 126 （ 9 ） 4423 - 4432 2022.01

Research paper (scientific journal), Joint Work, Last author, Corresponding author, Accepted
- Access to Document (DOI)
Enhanced Oxygen Reduction Activity of Size-Selected Platinum Subnanocluster Catalysts: Pt_n (n = 3 – 9)

kira Ohnuma, Koki Takahashi, Hironori Tsunoyama, Tomoya Inoue, Archana Velloth, Pei Zhao, Masahiro Ehara, Nobuyuki Ichikuni, Masao Tabuchi, and Atsushi Nakajima

Catalysis Science and Technology （RSC) in press 2021.12

Research paper (scientific journal), Joint Work, Accepted
Platinum Nanocluster Catalysts Supported on Marimo Carbon via Scalable Dry Deposition Synthesis

Naoyuki Hirata, Yui Katsura, Hiroyuki Gunji, Masahide Tona, Keizo Tsukamoto, Mika Eguchi, Toshihiro Ando, and Atsushi Nakajima

RSC Advances （RSC) 11 （ 62 ） 39216 - 39222 2021.12

Research paper (scientific journal), Joint Work, Accepted

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The development of efficient fuel cells greatly promotes reducing the consumption of fossil energy, and it is crucial to enhance the platinum (Pt) catalytic activity by optimizing both the nanoparticle size and support effect. In this study, we generate a smaller and uniform size of naked Pt nanocluster (NC) catalystsviaa dry process in the gas phase, and using the direct powder embedded trapping method, the Pt NCs arespatioselectivelysupported on Marimo carbon (MC) that comprises a high density of carbon nanofilaments. At a minimum Pt loading of 0.05 mgPtcm−2for both the anode and cathode in a single cell configuration, a membrane-electrode assembly (MEA) formed by the dry-deposition Pt-NC(d)/MC exhibits superior power density (rated) of 0.105 gPtkW−1at a current density of 1.2 A cm−2, which is better output power density than the conventional MEA formed by Pt catalystsviaa wet process. The origin of the improved performance is investigated using transmission electron microscopy; dry-deposition Pt catalysts that are monodispersely loaded on the outer surface of MC can facilitate not only the gas reaction but also leaving the generated water. The present results demonstrate that the dry deposition of Pt NCs on MC can be used as a scalable catalyst synthesis method to reduce the Pt loading.
- Access to Document (DOI)
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, ISSN 19327447

　View Summary

Nanocluster assembled films have attracted great interest for designing nanostructured materials with unique electromagnetic properties through a bottom-up approach. Superatoms of group-5 metals (MV = V, Nb, and Ta) encapsulating silicon (Si) cage nanoclusters (MV@Si16), which are synthesized by high-power impulse magnetron sputtering technique, can be efficiently generated to form assembled films. Temperature-dependent current-voltage (I-V) characteristics of the MV@Si16 assembled films revealed that the electrical conduction mechanism is not band transport but hopping transport with Efros-Shklovskii variable range hopping for all central MV atoms. The results show that electrons involved in conduction are strongly correlated to localized electronic states; this correlation arises because of not only the geometrical disordering in noncrystalline assembled films but also the electronic nature of a superatomic 1H orbital with multiple nodes. The localization length depends on the specific MV and is several times the radius of MV@Si16 (0.45 nm); it is the largest for Ta (2.2 nm) and the smallest for Nb (0.8 nm), revealing a periodicity of superatoms.
- Access to Document (DOI)

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

Fabrication of electronic functional thin layers with metal-atom encapsulating silicon nanocluster superatom

Nakajima, Atsushi

学事振興資金研究成果実績報告書（慶應義塾大学) 2021
Creation of composite thin film composed of caged nanocluster and elucidation of its thermoelectric properties

Nakajima, Atsushi

科学研究費補助金研究成果報告書 2019
Study on advanced interface formation with functional nanocluster monolayers and their electronic properties

Nakajima, Atsushi

科学研究費補助金研究成果報告書 2018
Studｙ on optical properties of organometallic nano-clusters on a substrate using optical wave guide spectroscopy

Nakajima, Atsushi

科学研究費補助金研究成果報告書 2010

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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

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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>

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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)

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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

2002.10

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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

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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

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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

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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

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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

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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 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.
Chemical Physics Letters Most Cited Paper 2003-2007 Award

2008.10, Elsevier

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