Exploitation and Exploration of Organic Superconductors

有机超导体的开发与探索

基本信息

批准号：
60470004
负责人：
SAITO Gunzi
金额：
$ 3.78万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

项目摘要

We have studied chemical and physical properties of organic superconductors of <(TMTSF)_2> X and BEDT-TTF complexes, and other organic conductors for the purposes to understand the correlation between the physical and structural properties of the component compounds and the physical properties of the molecular assemblies in order to explore new organic superconductors. Our group has done the syntheses of organic superconductors, organic metals and conductors, single crystal growths, optical studies, and ESR works. As for the other studies such as NMR works, magnetoresistance measurements, field induced SDW works, Raman, X-ray crystallographic works, X-ray diffuse scattering works, and physical measurements under high pressure were carried out by a cooperation with the other groups. Proton spin relaxation measurement (NMR) in the superconducting state of <(TMTSF)_2> <ClO_4> revealed that the superconductivity in this system is associated with the anisotropic order parameter vanishing al … More ong lines on the Fermi surface. The field induced SDW phase in <(TMTSF)_2> <ClO_4> was studied and two temperature-dependent structures in the magnetoresistance curve were newly found in the field range of 15-17T and 22-25T. Also Shubnikov-de Haas like small oscillations whose period and amplitude showed anomalous temperature and field dependence were found. In the ambient pressure superconductor of <beta> - <(BEDT-TTF)_2> <I_3> , two superconducting states were observed (a low- <T_c> state with <T_c> =1.1-1.5K and a high <T_c> state with <T_c> =7-8K). The high <T_c> state, which was originally discovered under a pressure of 1.3 kbar, is found to remain stable after removal of pressure. Moreover it has also been observed even without application of pressure. The ESR g value, linewidth, lineshape, and spin susceptibility of single crystal of the <alpha> and <beta> phases of <(BEDT-TTF)_2> <I_3> were each found to show marked temperature and angular dependences. In both phases, a Dysonian line-shape characteristic of conduction-electron spin resonance was observed at room temperature when the microwave electric field is applied parallel to the quasi-two-dimensional conducting plane of the crystal. A number of BEDT-TTF complexes were newly synthesized ( <(beta)> '- <I_3> , <delta> -Au <Br_2> , -Au <Cl_2> -Au <Cl_4> , -Cu <(SCN)_2> etc.) and their crystal structures and physical properties were studied. A series of tetrakis(n-alkylchalcogeno)tetrachalcogenafulvalene (chalcogene=sulfur, selenium, tellurium) was synthesized and their chemical, physical, and structural properties were studied. A number of charge transfer complexes of tetrakis(n-methylchalcogeno)-TTF, azaTCNQ, HCBD, <F_4> TCNQ, BTDA-TCNQ, semicapped <C_6> <S_8> compound was synthesized and electrical conductivities other physical properties, and crystal structures of them were studied. Less

我们研究了<(TMTSF)_2> X和BEDT-TTF配合物以及其他有机导体的有机超导体的化学和物理性质，以了解组分化合物的物理和结构性质与物理性质之间的相关性。我们课题组开展了有机超导体、有机金属和导体的合成、单晶生长、光学研究和ESR工作。与其他课题组合作开展了核磁共振工作、磁阻测量、场感应SDW工作、拉曼、X射线晶体学工作、X射线漫散射工作、高压物理测量等工作。 <(TMTSF)_2> <ClO_4> 超导态下的 NMR）揭示了该系统中的超导性与各向异性有序参数在沿线的消失有关。研究了<(TMTSF)_2><ClO_4>中的费米面，并在15-17T和22-25T磁场范围内新发现了两个与温度相关的结构。在<β>-的环境压力超导体中发现了类似哈斯的小振荡，其周期和振幅表现出异常的温度和场依赖性。 <(BEDT-TTF)_2> <I_3> ，观察到两种超导状态（<T_c> =1.1-1.5K 的低 <T_c> 状态和 <T_c> =7-8K 的高 <T_c> 状态）最初在 1.3 kbar 压力下发现的高 <T_c> 状态在去除压力后也被发现保持稳定。 <(BEDT-TTF)_2> <I_3> 的 <α> 和 <β> 相单晶的 ESR g 值、线宽、线形和自旋磁化率均显示出明显的温度和角度依赖性。在这两个相中，当微波电场平行于晶体的准二维导电面施加时，在室温下观察到传导电子自旋共振的戴森线形特征。新合成了许多BEDT-TTF配合物( <(beta)> '- <I_3> , <delta> -Au <Br_2> , -Au <Cl_2> -Au <Cl_4> , -Cu <(SCN)_2>研究了一系列四(n-烷基硫属元素)四硫属元素富瓦烯(硫属元素=硫，合成了四(n-甲基硫属元素)-TTF、azaTCNQ、HCBD、<F_4> TCNQ、BTDA-TCNQ、半封端<C_6 等多种电荷转移配合物，并研究了它们的化学、物理和结构性质。 > 合成了<S_8>化合物，并对它们的导电性、其他物理性质、晶体结构进行了研究。