Design of photo-controllable superconductive nanoparticles

• Project/Area Number: 16H04195
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Organic and hybrid materials
• Research Institution: Keio University
• Principal Investigator: EINAGA Yasuaki 慶應義塾大学, 理工学部(矢上), 教授 (00322066)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥16,770,000 (Direct Cost: ¥12,900,000、Indirect Cost: ¥3,870,000); Fiscal Year 2018: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2017: ¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000); Fiscal Year 2016: ¥7,150,000 (Direct Cost: ¥5,500,000、Indirect Cost: ¥1,650,000)
• Keywords: フォトクロミック材料 / 光制御 / 界面 / 磁性 / 超伝導 / フォトクロミズム / 界面物性 / 薄膜 / 微粒子 / 表面・界面物性 / 超伝導材料・素子 / 光スイッチ

Outline of Final Research Achievements

We report preparation of a photoswitchable room-temperature ferromagnetic material using FePt nanoparti-cles protected with a photochromic spiropyran ligand. It showed room-temperature ferromagnetism and reversible switching of magnetization by 60% upon photochromic reaction of the spiropyran ligand. This gigantic pho-tomagnetic effect is explained as spiropyran’s large change in the dipole moment during photochromic reaction that tunes the magnitude of electron transfer at the interface. Furthermore, we demonstrate that magnetoresistance and voltage generation originating from the spin-charge conversion in metallic heterostructures can be manipulated by decorating the surface with selfassembled organic monolayers through the cooperative molecular field effect. We also demonstrate reversible phototuning of the spin-charge conversion through light-driven molecular transformations using a molecule that can photoisomerize between the trans and cis states.

Academic Significance and Societal Importance of the Research Achievements

現在利用されている磁性材料、超伝導材料等の物性を光で制御できることは、光エネルギーの有効利用、光の有効な特性を利用した新しい機能材料の開発という点で有意義である。特に、スピンに関連する物性を可逆に光で制御できる材料は、学術的にも世界的に盛んに研究開発されており、社会的にもその開発が待たれている。例えば、本研究で示した、室温強磁性における磁性の可逆な光制御は、「室温」で実現したという点で、学術的観点はもちろん、実用材料への展開まで期待される。一方、化学的手法によるスピン軌道相互作用の光制御は、これまでに報告例がなく、スピントロニクス分野にとって学術的意義が大きい。

Research Products

• [Int'l Joint Research] Russian Academy of Sciences(ロシア連邦)
• [Int'l Joint Research] Russian Academy of Sciences(ロシア連邦)
• [Journal Article] High-Temperature Cooperative Spin Crossover Transitions and Single-Crystal Reflection Spectra of [FeIII(qsal)2](CH3OSO3) and Related Compounds (2019)
  • Author(s): Takahashi Kazuyuki、Yamamoto Kaoru、Yamamoto Takashi、Einaga Yasuaki、Shiota Yoshihito、Yoshizawa Kazunari、Mori Hatsumi
  • Journal Title: Crystals Volume: 9 Issue: 2 Pages: 81-81
  • DOI: 10.3390/cryst9020081
  • NAID: 120006599239
  • Peer Reviewed / Open Access
• [Journal Article] Contribution of Coulomb Interactions to a Two-Step Crystal Structure Phase Transformation Coupled with a Significant Change in Spin Crossover Behavior for a Series of Charged FeII Complexes from 2,6-Bis(2-methylthiazol-4-yl)pyridine (2018)
  • Author(s): Takahashi Kazuyuki、Okai Mitsunobu、Mochida Tomoyuki、Sakurai Takahiro、Ohta Hitoshi、Yamamoto Takashi、Einaga Yasuaki、Shiota Yoshihito、Yoshizawa Kazunari、Konaka Hisashi、Sasaki Akito
  • Journal Title: Inorg. Chem. Volume: 57 Issue: 3 Pages: 1277-1287
  • DOI: 10.1021/acs.inorgchem.7b02721
  • NAID: 120006469075
  • Peer Reviewed
• [Journal Article] Molecular engineering of Rashba spin-charge converter (2018)
  • Author(s): Hiroyasu Nakayama, Takashi Yamamoto, Hongyu An, Kento Tsuda, Yasuaki Einaga, and Kazuya Ando
  • Journal Title: Science Advances Volume: 4 Issue: 3
  • DOI: 10.1126/sciadv.aar3899
  • Peer Reviewed / Open Access
• [Journal Article] Cooperative spin-crossover transition from three-dimensional purely π-stacking interactions in a neutral heteroleptic azobisphenolate FeIII complex with a N3O3 coordination sphere (2017)
  • Author(s): Suguru Murata; Kazuyuki Takahashi; Tomoyuki Mochida; Takahiro Sakurai; Hitoshi Ohta; Takashi Yamamoto; Yasuaki Einaga
  • Journal Title: Dalton Trans. Volume: 印刷中 Issue: 18 Pages: 5786-5789
  • DOI: 10.1039/c7dt01030c
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Gigantic Photomagnetic Effect at Room Temperature in Spiropyran-Protected FePt Nanoparticles (2017)
  • Author(s): Yamamoto Takashi、Yurieva Elena A.、Tsuda Kento、Hosomi Tomoko、Aldoshin Sergey M.、Einaga Yasuaki
  • Journal Title: Phys. Status Solidi (RRL) Volume: 11 Issue: 9 Pages: 1700161-1700161
  • DOI: 10.1002/pssr.201700161
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spin-Singlet Transition in the Magnetic Hybrid Compound from a Spin-Crossover Fe(III) Cation and π-Radical Anion (2017)
  • Author(s): Takahashi Kazuyuki、Sakurai Takahiro、Zhang Wei-Min、Okubo Susumu、Ohta Hitoshi、Yamamoto Takashi、Einaga Yasuaki、Mori Hatsumi
  • Journal Title: Inorganics Volume: 5 Issue: 3 Pages: 54-54
  • DOI: 10.3390/inorganics5030054
  • Peer Reviewed / Open Access
• [Journal Article] Preparation of dihydroquinazoline carbohydrazone Fe(ii) complexes for spin crossover (2016)
  • Author(s): Shen Fu-Xing、Huang Wei、Yamamoto Takashi、Einaga Yasuaki、Wu Dayu
  • Journal Title: New J. Chem. Volume: 40 Issue: 5 Pages: 4534-4542
  • DOI: 10.1039/c5nj03095a
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Charge-Transfer Phase Transition of a Cyanide-Bridged FeII/FeIII Coordination Polymer (2016)
  • Author(s): Kuirun Zhang, Soonchul Kang,* Zi-shuo Yao, Kazusa Nakamura, Takashi Yamamoto, Yasuaki Einaga, Nobuaki Azuma, Yuji Miyazaki, Motohiro Nakano, Shinji Kanegawa, Osamu Sato*
  • Journal Title: Angew. Chem. Int. Ed. Volume: 55 Issue: 20 Pages: 6047-6050
  • DOI: 10.1002/anie.201601526
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Co-Fe Prussian Blue Analogue Intercalated into Diamagnetic Mg-Al Layered Double Hydroxides (2016)
  • Author(s): Zhang Cuijuan、Yamamoto Takashi、Einaga Yasuaki
  • Journal Title: Nanomater. Nanotech. Volume: 6 Pages: 26-26
  • DOI: 10.5772/63276
  • Peer Reviewed / Open Access
• [Journal Article] The Role of Coulombic Interactions for Spin Crossover Behaviors and Crystal Structural Transformation in Novel Anionic Fe(III) Complexes from a π-Extended ONO Ligand (2016)
  • Author(s): S. Murata, K. Takahashi, T. Sakurai, H. Ohta, T. Yamamoto, Y. Einaga, Y. Shiota, K. Yoshizawa
  • Journal Title: Crystals Volume: 6 Issue: 5 Pages: 49-64
  • DOI: 10.3390/cryst6050049
  • NAID: 120005756111
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Enhancement of the coercivity in Co-Ni layered double hydroxides by increasing basal spacing (2016)
  • Author(s): C. Zhang, T. Tsuboi, H. Namba, Y. Einaga, T. Yamamoto
  • Journal Title: Dalton Trans. Volume: 45 Issue: 34 Pages: 13324-13331
  • DOI: 10.1039/c6dt01723a
  • Peer Reviewed
• [Presentation] アゾベンゼンで保護したAu25量体ナノクラスターの磁気物性 (2016)
  • Author(s): 津田 健人・新堀 佳紀・根岸 雄一・山本 崇史・栄長 泰明
  • Organizer: 日本化学会第97春季年会
• [Presentation] 新規中性ヘテロレプティック鉄錯体の構造と物性 (2016)
  • Author(s): 村田 優・高橋 一志・櫻井 敬博・太田 仁・山本 崇史・栄長 泰明
  • Organizer: 日本化学会第97春季年会
• [Book] Photon-Working Switches (2017)
  • Author(s): Takashi Yamamoto, Keisuke Natsui, and Yasuaki Einaga,
  • Total Pages: 464
  • Publisher: Springer
• [Remarks] 栄長研究室webサイト
  • URL: http://www.chem.keio.ac.jp/~einaga-lab/