Design and relavization of photo-induced magnetic pole inverison

光感磁极反转的设计与重构

• 批准号: 12440096
• 负责人: HASHIMOTO Kazuhiro
• 金额: $ 8.96万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12440096/
• 关键词: Photo magnetism; photo-induced magnetic pole inversion; Ferromagnetism; molecule-based magnet; Cyaro-bridged metal complex; 時間発展型相転移; 非平衡現象; 光誘導起構造相転移; スピン転移; シアノ金属錯体; パルスレーザー光; 光誘起磁極反転; プルシアンブルー類似体

To prepare a new magnetic material showing photo-induced magnetic pole inversion, we have studied opto-functionalities of several metal complexes. The photomagnetic effect of the mixed-valence compound Cu^<II>_2 [Mo^<IV>(CN)_8]_8H_2O was observed. The UV-VIS spectra showed the intervalence transfer (IT) band between Mo^<IV>-CN-Cu^<II> and Mo^V-CN-Cu^I around 500 nm. When the paramagnetic compound was irradiated by a filtered blue light of a Xe lamp at 5 K, the irradiated sample exhibited a spontaneous magnetization with a Curie temperature of 17 K. By annealing the irradiated sample above 200 K, the magnetic property of this sample returned to the initial state. Moreover, a new type of cyano-bridged Co-W bimetallic assembly, Cs^I[{Co^<II>(3-cyanopyridine)_2}{W^V(CN)_8}]H_2O was synthesized. This compound exhibited a temperature-induced phase transition and a photo-induced magnetization. Irradiating with light induced a spontaneous magnetization with a magnetic phase transition temperature at 30 K. This photo-induced magnetization is due to the phase transition from Co^<III>(LS ; S = 0)-W^<IV>(S = 0) to Co^<II>(HS ; S = 3/2)-W^V(S = 1/2) phases by the irradiation. Furthermore, we observed the photomagnetic effect in Rb_<0.91>Mn_<1.05>[Fe(CN)_6]・0.6H_2O ferromagnet. Magnetization of this system was reduced by irradiation with only one-shot of laser pulse (532 nm) at 3 K. Infrared spectra before and after the irradiation indicated that this photomagnetic effect was caused by a photo-induced phase transition from the Fe(II)-CN-Mn(III) phase to the Fe(III)-CN-Mn(II) phase.

为了制备一种具有光致磁极反转的新型磁性材料，我们研究了几种金属配合物的光功能。研究了混合价化合物Cu^<II>_2 [Mo^<IV>(CN)_8]_8H_2O的光磁效应。紫外可见光谱显示Mo^<IV>-CN-Cu^<II>和Mo^V-CN-Cu^I之间的价间转移（IT）带在500 nm左右。顺磁性化合物在5 K时用Xe灯的滤光蓝光照射，样品表现出自发磁化，居里温度为17 K。经200 K以上退火后，样品的磁性能恢复到初始状态。此外，还合成了一种新型的氰基桥接Co-W双金属复合物Cs^I[{Co^<II>（3-氰吡啶）_2}{W^V(CN)_8}]H_2O。该化合物表现出温度诱导相变和光诱导磁化。光照射诱导自发磁化，磁相变温度为30k。这种光致磁化是由于Co^<III>(LS; S = 0)-W^<IV>(S = 0)到Co^<II>(HS; S = 3/2)-W^V（S = 1/2）相在辐照下发生相变。此外，我们还在Rb_<0.91>Mn_<1.05>[Fe(CN)_6]·0.6H_2O铁磁体中观察到光磁效应。仅用一次532 nm的激光脉冲在3k下照射就能降低该体系的磁化强度。辐照前后的红外光谱表明，这种光磁效应是由Fe(II)-CN-Mn（III）相到Fe(III)-CN-Mn（II）相的光诱导相变引起的。

项目成果

S. Ohkoshi, M. mizuno, G. J. Hung, K. Hashimoto: "Magnetooptical effects of room temperature molecular based magnetic films composed of vanadium hexacyarochrmates"J. Phys. Chem. B. 104. 9365 (2000)

S. Ohkoshi、M. mizuno、G. J. Hung、K. Hashimoto：“由六氰基铬酸钒组成的室温分子基磁性薄膜的磁光效应”J。

S. Ohkoshi, H. Tokoro, M. Utsunomiya, M. Mizuno, M. Abe, K. Hashimoto: "Observation of spin transition in an actahedrally coordinated manganese (II) compound"J. Phys. Chem. B. 106. 2423 (2002)

S. Ohkoshi、H. Tokoro、M. Utsunomiya、M. Mizuno、M. Abe、K. Hashimoto：“二面体配位锰 (II) 化合物中自旋跃迁的观察”J。

S.Ohkoshi, M.Mizuno, G.J.Hung, K.Hashimoto: "Magnetooptical effects of room temperature molecular-based magnetic films composed of vanadium hexacyanochromates"J. Phys. Chem. B. 104. 9365 (2000)

S.Ohkoshi，M.Mizuno，G.J.Hung，K.Hashimoto：“由六氰基铬酸钒组成的室温分子基磁性薄膜的磁光效应”J。

S.Ohkoshi, K.Hashimoto, et al.: "Observation of Spin transition in an octahedrally coordinated manganese (II) compound"J.Phys.Chem B. 106. 2423 (2002)

S.Ohkoshi、K.Hashimoto 等人：“八面体配位锰 (II) 化合物中自旋跃迁的观察”J.Phys.Chem B. 106. 2423 (2002)

S.Ohkoshi, K.Hashimoto et al.: "The observation of two compensation temperatures in a cobalt-manganese hexacyanochromate"Physica B. (in press). (2003)

S.Ohkoshi、K.Hashimoto 等人：“六氰基铬酸钴锰中两个补偿温度的观察”Physica B.（出版中）。