Development of Room-Temperature Molecular/Organic Ferromagnets and Estimation of Their Low-Frequency Shielding Materials

室温分子/有机铁磁体的开发及其低频屏蔽材料的评估

基本信息

批准号：
08555224
负责人：
SUGIMOTO Toyonari
金额：
$ 2.75万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

Three years ago we found out room-temperature ferromagnetic behavior in 1 : 2 mixed salts of TCNQ or TCNQF_4 with TCNQF_4 radical anion. The similar behavior was also recognized in 1 : 2 mixed salts of diethyl-substituted TCNQ or tetracyanonaphthoquinodimethane with their radical anions. This observation is quite remarkable, since the highest temperature of spin ordering is 36 K for purely organic ferromagnets and weak ferromagnets obtained so far. However, the saturation magnetization observed in these 1 : 2 mized salts is only 0.1% of the value (5,580 emu.mol^<-1>) obtained by one S=1/2 spin per formula unit.For the 1 : 2 mixed salt of dimethyl-substituted TCNQ with its radical anion, metal-like high electrical conductivity was observed together with room-temperature ferromagnetic behavior. Accordingly, this mixed salt can be regarded as an analogue to a ferromagnetic metal such as iron, cobalt and nickel. Much interest is directed toward the interaction between the interaction between conducting pi electron and localized d spin, while this mixed salt should be noted as a new molecular system involving both conducting pi electron and localized pi spin.In summary, room-temperature ferromagnetic behavior can be in common observed in 1 : 2 mixed salts of TCNQ, substituted TCNQ's and TCNQ analogue, but the mechanism of spin ordering remains to be still not elucidated. Further study is necessary in order to elucidate the mechanism of spin ordering and to search a room-temperature (ferro)magnet with larger saturation magnetization.

三年前，我们在1：2的TCNQ或TCNQF_4的混合盐中发现了带有TCNQF_4自由基阴离子的室温铁磁行为。在1：2二乙基取代的TCNQ的混合盐或四苯二氨基甲烷二甲烷的1：2混合盐中也识别出类似的行为。该观察结果非常引人注目，因为对于迄今为止获得的纯有机铁磁体和弱铁磁体的最高温度温度为36 K。但是，在这1：2中观察到的饱和磁化仅是一个s = 1 = 1/2旋转的盐的0.1％（5,580 emu.mol^<-1>）。观察到二甲基取代的TCNQ及其自由基阴离子，金属样高电导率的盐与室温铁磁行为一起观察到。因此，这种混合盐可以被视为与铁，钴和镍等铁磁金属的类似物。引起了很大的兴趣，是指导PI电子与局部D自旋之间的相互作用之间的相互作用，而这种混合盐应被视为一种新的分子系统，该系统涉及导电PI电子和局部PI旋转。摘要，室内体温铁磁行为可以在TCNQ的1：2混合盐，取代TCNQ和TCNQ类似物中是共同观察到的，但是旋转顺序的机理仍然尚未阐明。为了阐明自旋顺序的机理并搜索具有较大饱和磁化的室温（Ferro）磁铁的机理，需要进一步研究。