磁気および電気的双安定状態を備えた金属錯体の合理的設計と外場制御

• Project/Area Number: 18350028
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Inorganic chemistry
• Research Institution: The University of Tokyo
• Principal Investigator: 大越 慎一 The University of Tokyo, 大学院・理学系研究科, 教授 (10280801)
• Project Period (FY): 2006 – 2008
• Project Status: Completed (Fiscal Year 2008)
• Budget Amount: ¥17,280,000 (Direct Cost: ¥14,700,000、Indirect Cost: ¥2,580,000); Fiscal Year 2008: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2007: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2006: ¥6,100,000 (Direct Cost: ¥6,100,000)
• Keywords: 相転移 / 外場制御 / 金属錯体 / 可逆光磁性 / 電荷移動 / 強磁性体 / 光相転移材料 / 光スイッチング磁石 / 外場制御(光・磁気・電気) / 準安定相 / ヤーン・テラー効果 / 双安定状態 / 磁性体

Research Abstract

現在、オプトエレクトロニクス用の材料として、光で物質変化する材料の研究開発が活発に進められている。光により直接的に磁気特性をスイッチングできる磁性材料は、光による書き込みが可能なため、高密度化および高速化が可能であるため、光通信や光メモリーおよび光コンピューターなどの光磁気メモリー媒体や光アイソレター素子などへの応用が期待されている。本研究課題では、外場(磁場、電場、光)制御による新しい現象を実現するため、磁気および電気的双安定状態を備えた金属錯体の合理的設計と外場制御に関する研究を行った。その中で、CoイオンWイオンがシアノ基で架橋した3次元構造体CO_3[W(CN)_8]_2(ピリミジン)_4・6H_2Oにおいて、2種類の波長の光により強磁性と常磁性の可逆的なスイッチングをする光磁性現象を示すことを見出した。この物質に840nmの光を照射すると、色相が青色から赤色へと変化すると共に、T_cが40K、H_cが12kOeの強磁性相に転移することが観測された。光照射前の金属イオンの電子状態はCo^<III>(S=0)-W^<IV>(S=0)状態をとっているが、840nm光照射によって、W^<IV>からCo^<III>への電荷移動が起こり、Co^<II>(S=3/2)-W^V(S=1/2)状態に光誘起相転移することが分かった。一方、光誘起強磁性相に532nm光を照射すると磁化は消失し、常磁性状態に戻ることが分かった。この逆光反応は、532nm光励起により逆電荷移動(Co^<II>→W^V)が起こっていることに起因している。観測された光誘起強磁性相の磁気相転移温度および保磁力の値は、これまでに報告されている光磁石の中で最も優れた値である。本物質でこのような高い性能が観測された理由としては、(i)この物質が、電荷移動型スピン相転移物質(注5)であること、(ii)磁性金属イオンが3次元シアノ架橋型構造をとっているためスピン間の磁気的相互作用が強く働いたこと、また(iii)非磁性状態と磁石状態で吸収する光の波長が大きく異なっていることによると考えられる。

Research Products

• [Journal Article] Fabrication of a high temperature superconductormicro-superconducting-quantum-interferende-device magnetometer for magnetic hysteresis measurements (2008)
  • Author(s): K. Takeda, H. Mori, A. Yamaguchi, H. Ishimoto, T. Nakamura, S. Kuriki, T. Hozumi, S. Ohkoshi
  • Journal Title: J. Appl. Phys. 103
  • Peer Reviewed
• [Journal Article] Dynamics of charge-transfer pairs in the cyano-bridged Co^<2+>-Fe^<3+> transition-metal compound (2008)
  • Author(s): H. Kamioka, Y. Moritomo, W. Kosaka, S. Ohkoshi
  • Journal Title: Phys. Rev. B 77
  • Peer Reviewed
• [Journal Article] Fine tuning of second order nonlinear activity with rubidium manganese hexacyanoferrates (2008)
  • Author(s): S. Ohkoshi, T. Matsuda, S. Saito, T. Nuida, H. Tokoro
  • Journal Title: J. Phys. Chem. C 112 Pages: 13095-13098
  • Peer Reviewed
• [Journal Article] Three-Dimensional Manganese-Octacyanoniobate-based Pyroelectric Ferrimagnet Manganese-Pyrazin-Octacyanoniobate (2008)
  • Author(s): W. Kosaka, K. Hashimoto, S. Ohkoshi
  • Journal Title: Bull. Chem. Soc. Jpn. 81 Pages: 992-994
  • Peer Reviewed
• [Journal Article] Extended charge-transfer state of RbMh[Fe(CN)_6] (2007)
  • Author(s): K. Kato, Y. Moritomo, H. Tanaka, Tokoro, S. Ohkoshi, and M. Takata
  • Journal Title: J. Phys. Soc. Jpn 76 Pages: 123602-123602
• [Journal Article] Single Crystal of a Prussian Blue Analog based on Rubidium Manganese Hexacyanoferrate (2007)
  • Author(s): H. Tokoro, M. Shiro, K. Hashimoo, and S. Ohkoshi
  • Journal Title: Z. Anorg. Allg. chem 633 Pages: 1134-1134
• [Journal Article] Effect of pressure on the magnetic behavior of the spin crossover Prussian Blue analogue CsFe[Cr(CN)_6] (2007)
  • Author(s): D. Papanikolaou, W. Kosaka, S. Margadonna, H. Kagi, S. Ohlcoshi, and K. Prassides
  • Journal Title: J. Phys. Chem. C 111 Pages: 8086-8086
• [Journal Article] Photo-induced charge transfer phase transition in cesium manganese hexacyanoferrate (2007)
  • Author(s): T. Mastuda, H. Tokoro, K. Hashimoto, and S. Ohkoshi
  • Journal Title: J. Appl. Phys 101
• [Journal Article] Photo-induced charge tranfer phase transition of rubidium manganese hexacyanoferrate in ferromagnetic and paramagentic regions (2007)
  • Author(s): H. Tokoro, K. hashimoto, and S. Ohkoshi
  • Journal Title: J. Mag. Mag. Mater 310 Pages: 1422-1422
• [Journal Article] Change-transfer transition in a 2D cyano-brideged metal compound as investigated by synchrotron radiation X-ray (2007)
  • Author(s): J. Kim, Y. Moritomo, K. Kato, M. Takata, and S. Ohkoshi
  • Journal Title: Phys, rev. B 76 Pages: 14106-14106
• [Journal Article] Role of the intermediate state in the photo-induced peoess of Co-Fe cyanide (2007)
  • Author(s): Y. Moritomo, F. Nakada, H. Kamioka, t. Hozumi and S. Ohkoshi
  • Journal Title: Phys. Rev. B 75 Pages: 214110-214110
• [Journal Article] A high compensation temperature of 175 K in a vanadium hexacyano chromate-based magent (2007)
  • Author(s): S. Ohkoshi, T. Hozumi, M. Mizuno and K. Hashimoto
  • Journal Title: Chem Lett 36 Pages: 932-932
• [Journal Article] Calorimetric investigation of equilibrium and non-equilibrium propertis of the switchable Prussian Blue analog Na_<0.32>Co[Fe(CN)_6]_<0.74>・3.4H_20 (2007)
  • Author(s): M. Castro, J. A. Rodriguez-Velamazan, K. Boukheddaden, F. Varret, H. Tokoro, and S. Ohkoshi
  • Journal Title: Europhysics Lett 79 Pages: 27007-27007
• [Journal Article] Observation of a phase transition of cesium manganese hexacyanoferrates by x-ray absorption spectroscopy (2007)
  • Author(s): K. Ishiii, t. Iwazumia, T. Mastuda, H. Tokoro, K. Hashimoto, and S. Ohkoshi
  • Journal Title: J. Phys. Chem. Solid 68 Pages: 2158-2158
• [Journal Article] Coexistence of Ferroelectricity and Ferromagnetism in a Rubidium Manganese Hexacyanoferrate (2007)
  • Author(s): S. Ohkoshi, H. Tokoro, T. Matsuda, H. Takahashi, H. Irie, and K. Hashimoto
  • Journal Title: Angew. Chem. Int. Ed. 46 Pages: 3238-3241
• [Journal Article] (Poly[triaquaocta-μ-cyano-dicopper (II) molybdate (IV) monohydrate (2007)
  • Author(s): Y. Zhang, T. Hozumi, K. Hashimoto, and S. Ohkoshi
  • Journal Title: Acta Cryst. E 63
• [Journal Article] Thermal spin transition investigated by spectroscopic ellipsometry in [Fe(NH_2-trz)_3]Br_2 (2007)
  • Author(s): E.D. Loutete-Dangui, F. Varret, E. Codjovi, P.R. Dahoo, H. Tokoro, S. Ohkoshi, C. Eypert, J.F. Letard, J.M. Coanga, and K. Boukheddaden
  • Journal Title: Phys. Rev. B 75
• [Journal Article] Photoinduced magnetization with a high Curie temperature and a largecoercive field in a cyano-bridged cobalt-tungstate bimetallic assembly (2006)
  • Author(s): S. Ohkoshi, S. Ikeda, T. Hozumi, T. Kashiwagi, and K. Hashimoto
  • Journal Title: J. Am. Chem. Soc. 128 Pages: 5320-5321
• [Journal Article] Huge thermal hysteresis loop and a hidden stable phase in a charge-transfer phase transition of Rb_<0.64>Mn[Fe(CN)_6]_<0.88>・1.7H_2O (2006)
  • Author(s): H. Tokoro, S. Miyashita, K. Hashimoto, and S. Ohkoshi
  • Journal Title: Phys. Rev. B 73
• [Journal Article] X-ray illumination induced Fe (II) Spin Crossover in the Prussian Blue Analogue Cesium Iron Hexacyanochromate (2006)
  • Author(s): D. Papanikolaou, S. Margadonna, W. Kosaka, S. Ohkoshi, M. Brunelli, and K. Prassides
  • Journal Title: J. Am. Chem. Soc. 128 Pages: 8358-8363
• [Journal Article] Synthesis and superparamagnetic property of a Co-Cr Prussian blue analogue nanoparticles inside Nafion Membrane (2006)
  • Author(s): W. Kosaka, M. Tozawa, K. Hashimoto, and S. Ohkoshi
  • Journal Title: Inorg. Chem. Commun. 9 Pages: 920-922
• [Journal Article] Crystal structure and nonlinear optical effect of a pyroelectric crystal composed of a cyano-bridged Cu-Mo assembly (2006)
  • Author(s): T. Hozumi, T. Nuida, K. Hashimoto, and S. Ohkoshi
  • Journal Title: Cryst. Growth Des. 6 Pages: 1736-1737
• [Journal Article] Crystal Structures of Photo-induced Phase and Rapidly-cooled Phase in Rb_<0.73>Mn[Fe(CN)_6]_<0.91>・1.4H_2O Prussian Blue Analog (2006)
  • Author(s): H. Tokoro, T. Matsuda, S. Miyashita, K. Hashimoto, and S. Ohkoshi
  • Journal Title: J. Phys. Soc. Jpn. 75
  • NAID: 110004799234
• [Journal Article] Charge-transfer phase transition and zero thermal expansion in cesium manganese hexacyanoferrate (2006)
  • Author(s): T. Matsuda, H. Tokoro, K. Hashimoto, and S. Ohkoshi
  • Journal Title: Dalton Trans. Pages: 5046-5050
• [Journal Article] 鉄錯体磁性体および鉄酸化物磁性体の新規機能性に関する研究 (2006)
  • Author(s): 大越慎一
  • Journal Title: メスバウアー分光研究会会誌 7 Pages: 8-9
• [Presentation] Recent magnetooptical phenomena in magnetic materials (2008)
  • Author(s): S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Reversible photomagnetic effect in rubidium manganese hexacyanoferrate (2008)
  • Author(s): R. Fukaya , K. Ohki, M. Nagajima, H. Tokoro, S. Ohkoshi, T. Suemoto
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Time-resolved spectroscopy of Fe-Co nano particle (2008)
  • Author(s): H. Kamioka, Y. Moritomo, W. kosaka, S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Metamagnetism in two dimensional layered CuII-WV bimetallic assembly (2008)
  • Author(s): S. Kaneko, Y. Tsunobuchi, S. Sakurai, S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Synthesis of cyano-bridged nanoparticles inside Nafion mambrane (2008)
  • Author(s): W. Kosaka, K. Hashimoto, S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Thermal phase transitions on Mn-Fe Prussian blue analogues (2008)
  • Author(s): T. Matsuda, H. Tokoro, K. Hashimoto, S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Constriction of functional rare earth complex (2008)
  • Author(s): K. Nakabayashi, S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Light-induced charge transfer phase transition in cesium manganese hexacyanoferrate magnetic material (2008)
  • Author(s): T. Matsuda, K. Nakagawa, H. Tokoro, S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Nonlinear optical susceptibilities for magnetization-induced second harmonic generation in ferromagnetic Prussian blue film (2008)
  • Author(s): T. Nuida, J. Shimura, K. Ikeda, K. Hashimoto, S. Ohkoshi
  • Organizer: Nonlinear optical susceptibilities for magnetization-induced second harmonic generation in ferromagnetic Prussian blue film
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] A control of second harmonic generation with rubidium manganese hexacyanoferrates (2008)
  • Author(s): S. Saito, T. Matsuda, T. Nuida, H. Tokoro, S. Ohkoshi
  • Organizer: International conference recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Development of a high temperature superconuctor micro-SQUID magnetometer for magnetization measurement of single micro sized magnets (2008)
  • Author(s): K. Takeda, H. Mori, A. Yamaguchi, H. Ishimoto, T. Nakamura, S. Kuriki, T. Hozumi, S. Ohkoshi
  • Organizer: International confernce recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Presentation] Alchol vapor sensitivity in copper-tungsten porous magnets (2008)
  • Author(s): Y. Tsunobuchi, K. Hashimoto, S. Ohkoshi
  • Organizer: International confernce recent optical materials (ICROM 2008)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2008-04-03
• [Book] チャンピオンレコードを持つ金属錯体最前線 (2006)
  • Author(s): 大越慎一(共著)
  • Total Pages: 9
  • Publisher: 化学同人
• [Remarks]
  • URL: http://www.chem.s.u-tokyo.ac.jp/users/ssphys/index.html