Magnetic properties and electronic structure of organic crystals.

有机晶体的磁性和电子结构。

• 批准号: 02403001
• 负责人: KINOSHITA Minoru
• 金额: $ 19.2万
• 依托单位: ISSP, Univ. of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02403001/
• 关键词: Magnetic properties; Organic ferromagnet; Spin quantum effect; p-NPNN; Nitronyl nitroxide; Magneto-structural correlation; 量子効果; 1次元強磁性体; pーNPNN; 多形; 有機伝導体; 異方性; 磁気的相互作用; 有機ーハロゲノ金属酸錯体; 錯体; gー因子; 短距離磁気秩序

The magnetic properties of TTF and BEDT-TTF complexes with MX_4 (M=Mn, Co, Cu; X=Cl, Br) and charge transfer complexes of TTF having an organic radical substituents were examined to see magnetic interaction between conduction electrons and localized electrons. In EPR experiments, g-shift with temperature has been observed in the BEDT-TTF-CoCl_4, BEDT-TTF-MnCl_4 and TTF-MnCl_4 systems. An indication of short range magnetic order was also found in the system of TTF-MnCl_4.2. The orthorhombic phase of p-nitrophenyl nitronyl nitroxide (p- NPNN) has been found to undergo a transition towards ferromagnetic ordered state at 0.6 K. This is the first example of bulk ferromagnetism in organic compound composed of light elements(H, C, N and O). The ferromagnetism has been comfirmed by the measurements of ac susceptibility, heat capacity, hysteresis curve and spontaneous magnetization below Tc. 3. Thecommon structural feature for ferromagnetic coupling has been deduced from the studies of magneto-structural correlation in about 20 derivatives of phenyl nitronyl nitroxide. 4. The magnetic properties of a biradical and a triradical based on nitronyl nitroxide, the ground spin states of which are triplet and quartet respectively, have also been studied to see the effect of competition between the intramolecular exchange interaction and intermolecular exchange interaction. In particular, the biradical showed very complex magnetic behavior accompanying crystal structure change with temperature and spin quantum effect.

研究了TTF和BEDT-TTF与MX_4（M=Mn，Co，Cu; X=Cl，Br）的配合物以及TTF与有机基团取代的电荷转移配合物的磁性，以观察导电电子和局域电子之间的磁相互作用。在EPR实验中，在BEDT-TTF-CoCl_4、BEDT-TTF-MnCl_4和TTF-MnCl_4体系中观察到g值随温度的变化。在TTF-MnCl_4.2体系中也发现了短程磁有序的迹象。对硝基苯硝酰基氮氧化物（p-NPNN）的正交相在0.6K时发生了向铁磁有序态的转变。这是由轻元素（H、C、N和O）组成的有机化合物中体铁磁性的第一个例子。通过交流磁化率、热容、磁滞曲线和Tc以下自发磁化强度的测量，证实了其铁磁性。3.通过对20种苯基硝酰基氮氧自由基衍生物的磁结构相关性研究，推断出铁磁耦合的共同结构特征。4.基于硝酰基氮氧化物的双自由基和三自由基的磁性，其基态分别为三重态和四重态，也被研究，以观察分子内交换相互作用和分子间交换相互作用之间的竞争效应。特别是，双自由基表现出非常复杂的磁行为伴随着晶体结构的变化与温度和自旋量子效应。

项目成果

高橋 實: "Mean-field theory of quasi one-dimensional Heisenberh magnet γ-phase p-NPNN" Journal of the Physical Society of Japan. 61. 3745-3751 (1992)

高桥稔：“准一维海森伯磁体 γ 相 p-NPNN 的平均场理论”日本物理学会杂志 61. 3745-3751 (1992)。

M.Tamura,D.Shiomi,Y.Hosokoshi,N.Iwasawa,K.Nozawa,M.Kinoshita,H.Sawa and R.Kato: "Magnetic properties of phenyl nitronyl nitroxides" Molecular Crystal and Liquid Crystal.

M.Tamura、D.Shiomi、Y.Hosokoshi、N.Iwasawa、K.Nozawa、M.Kinoshita、H.Sawa 和 R.Kato：“苯基硝基硝基氧的磁性”分子晶体和液晶。

中澤 康浩: "Low temperature magnetic prorerties of ferromagnetic organic radical,p-NPNN" Physical Review. B46. 8906-8914 (1992)

Yasuhiro Nakazawa：“铁磁性有机自由基的低温磁性，p-NPNN”物理评论 B46（1992）。

T.Sugano,T.Fukasawa and M.Kinoshita: "Magnetic interactions among unpaired electrons in charge-transfer complexes of organic donors having a neutral radical" Synthetic Metals. 43(1 & 2). 3281-3284 (1991)

T.Sugano、T.Fukasawa 和 M.Kinoshita：“具有中性自由基的有机供体的电荷转移复合物中不成对电子之间的磁相互作用”合成金属。

D.Shiomi,M.Tamura,H.Sawa,R.Kato and M.Kinoshita: "Magnetic properties of an organic biradical, m-BNN: m-Phenylene bis(alpha-nitronyl nitroxide)" Journal of the Physical Society of Japan. 62(1). 289-300 (1993)

D.Shiomi、M.Tamura、H.Sawa、R.Kato 和 M.Kinoshita：“有机双自由基 m-BNN 的磁性：间亚苯基双（α-硝酰基硝基氧）” 日本物理学会杂志