Spin Gap States in Exotic Low-Dimensional Molecular Magnets

奇异低维分子磁体中的自旋间隙态

• 批准号: 09440236
• 负责人: AWAGA Kunio
• 金额: $ 9.34万
• 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: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440236/
• 关键词: Low-Dimensional Magnet; Spin Gap; Kagome Lattice; Molecular Bistability; スピンラダー

(1) We studied the organic radical, m-MPYNN, that formed an S=1 Kagome lattice in the crystals of m-MPYNN・X (X=I, ClOィイD24'ィエD2 BFィイD24ィエD2). The ground state was a spin gap state with Δ/kィイD2BィエD2=0.24 K. The extension of the methyl group in m-MPYNN resulted in collapses of the Kagome lattice and the spin gap state.(2) [Ni(dmit)ィイD22ィエD2] formed a spin-ladder structure in the crystal of p-EPYNN・[Ni(dmit) ]ィイD22ィエD2], which was a topic of in the study of low-dimensional magnetic materials, In this project we investigated a solid solution system p-EPYNN・[Ni(dmit) ]ィイD22ィエD2]ィイD21-xィエD2・[Au(dmit) ]ィイD22ィエD2]ィイD2xィエD2. The doping of non-magnetic [Au(dmit) ]ィイD22ィエD2]- brought about paramagnetic lattice defects in the spin ladder with a extended spin polarization.(3) We started the study of cyclic thioaminyl (NS) radicals and found a very interesting phase transition of TTTA. The phase transition occurred between a paramagnetic high-temperature phase and a diamagnetic low-temperature phase with a surprisingly large hysteresis loop. Since the room temperature was included in the loop, TTTA exhibited room-temperature magnetic bistability.

(1)本文研究了在m-MPYNN·X（X=I，ClO_（24）O_（24基态为自旋能隙态，Δ/k =0.24 K。甲基在m-MPYNN中的延伸导致Kagome晶格和自旋能隙态的崩塌。(2)[Ni（dmit）D22 D2]在p-EPYNN·[Ni（dmit）] D22 D2]晶体中形成了一个自旋梯形结构，这是低维磁性材料研究的一个课题。本项目研究了p-EPYNN·[Ni（dmit）] D22 D2] D21-x D2·[Au（dmit）] D22 D2] D2 x D2固溶体系统。非磁性的[Au（dmit）] D22 D2]-的掺杂在具有扩展的自旋极化的自旋梯中带来顺磁晶格缺陷。(3)我们开始研究环硫代胺基（NS）自由基，并发现了一个非常有趣的相变TTTA。相变发生在顺磁性高温相和反磁性低温相之间，具有令人惊讶的大磁滞回线。由于环中包括室温，TTTA表现出室温磁双稳态。

项目成果

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T.Sekine 等人：“层状结构中自发磁化的观察……”Inorg Chem.37。

K.Awaga et al.: "High Pressure Effects on a Manganese Hexacyano..." Chem.Phys.Lett.293. 352-356 (1998)

K.Awaga 等人：“高压对六氰锰的影响……”Chem.Phys.Lett.293。

W. Fujita eral.: "Room Temperature Magnetic Bistability in"Science. 286. 261-262 (1999)

W. Fujita eral.：“科学中的室温磁双稳态”。

W.Fujita et al.: "Photoisomerization of Azobenzene Derivatives…" Mol.Cryst.Lig.Cryst.315. 29-34 (1998)

W.Fujita 等人：“偶氮苯衍生物的光异构化……”Mol.Cryst.Lig.Cryst.315 (1998)。

W. Fujita and K. Awaga: "Room-Temperature Magnetic Bistability in Organic Radical Crystals"Science. 286. 261-262 (1999)

W. Fujita 和 K. Awaga：“有机自由基晶体中的室温磁双稳定性”科学。