CONTROL OF ELECTRONIC STATES OF ORGANIC SUPERCONDUCTORS BY UNIAXIAL STRAIN METHOD

单轴应变法控制有机超导体的电子态

• 批准号: 14204033
• 负责人: KAGOSHIMA Seiichi
• 金额: $ 35.03万
• 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 (A)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14204033/
• 关键词: organic conductor; organic superconductor; Mott insulator; uniaxial compression; electrical conduction; maemetoresistance; x-ray diffraction; molecular synthesis

This research aims to reveal the relationship among superconductivity and various types of electronic state of organic superconductors by uniaxially compressing crystalline lattices only along the desired direction and controlling their crystal and electronic structures.In a series of organic conductors having a quarter-filled conduction band with the strong Coulomb correlation, the relationship among the metallic, charge-ordered, and superconducting states were clarified by systematic investigations of electrical transport properties, crystal and electronic structures under the uniaxial strain. We found that the band structure predominated the electronic state of α-(BEDT-TTF)_2XHg(SCN)_4, (X=K,NH_4). In θ-(BEDT-TTF)_2CsZn(SCN)_4,the newly synthesized α-(BEDT-TTF)_2CsCd(SCN)_4 and β-(BEDT-TTF)_2CsCd(SCN)_4,and β''-(DODHT)_2PF_6 synthesized by the Tokyo Metropolitan University group, however, their electronic states were found to be dominated by the charge ordering due to the long range … More Coulomb correlation. These results lead to a unified phase diagram of the electronic states of α-,θ-and β-types of organic conductor, In the half-filled band system, K-(BEDT-TTF)_2X [X=Cu(NCS)_2,Cu[N(CN)_2]Br,Cu_2(CN)_3] the on-site Coulomb correlation causes the Mott insulating state. We found that the deformation of their triangular lattice by the uniaxial compression controlled the electronic states and the spin-firustrating state to realize an increase in the superconducting critical temperature and a nonmagnetic spin state. These results suggested the importance of the spin fluctuations for the mechanism of superconductivity.In the development of new materials, we turned our attention to the intermolecular interaction of the iodine bonding and the hydrogen bonding of CH・・・O type to make the supramolecular structure that gives rise to new supramolecular conducting and superconducting materials. We developed a safe method to synthesize [1,3] diselenole derivative that served as a basic reagent for new materials syntheses and succeeded in synthesizing TTF derivatives having selenium. We developed also a series of crystals of supramolecular organic conductors that had effective arrangements of anisotropic molecular interactions based on the iodine bonding. We succeeded in synthesizing BEDO-TSeF, the last unexplored molecule belonging to the family of BEDT-TTF derivative and clarifying its basic structural and electronic basic properties. Less

本研究旨在通过仅沿所需方向单轴压缩晶格并控制其晶体和电子结构来揭示有机超导体的超导性和各种类型的电子态之间的关系。在一系列具有强库仑相关性的四分之一填充导带的有机导体中，通过电学的系统研究阐明了金属态、电荷有序态和超导态之间的关系。 单轴应变下的输运特性、晶体和电子结构。我们发现能带结构主导了α-(BEDT-TTF)_2XHg(SCN)_4, (X=K,NH_4)的电子态。然而，在θ-(BEDT-TTF)_2CsZn(SCN)_4中，新合成的α-(BEDT-TTF)_2CsCd(SCN)_4和β-(BEDT-TTF)_2CsCd(SCN)_4以及东京都立大学研究组合成的β''-(DODHT)_2PF_6， 由于长程库仑相关性，它们的电子态被发现由电荷排序主导。这些结果得到了α-、θ-和β-型有机导体电子态的统一相图，在半填充能带系统中，K-(BEDT-TTF)_2X [X=Cu(NCS)_2,Cu[N(CN)_2]Br,Cu_2(CN)_3]现场库仑相关导致莫特绝缘态。我们发现单轴压缩引起的三角晶格变形控制了电子态和自旋挫败态，从而实现了超导临界温度的升高和非磁性自旋态。这些结果表明了自旋涨落对于超导机理的重要性。在新材料的开发中，我们将注意力转向了CH···O型的碘键和氢键的分子间相互作用，以形成超分子结构，从而产生了新型超分子导电和超导材料。我们开发了一种安全的合成[1,3]二硒醇衍生物的方法，作为新材料合成的基本试剂，并成功合成了含硒的TTF衍生物。我们还开发了一系列超分子有机导体晶体，它们具有基于碘键的各向异性分子相互作用的有效排列。我们成功合成了BEDT-TTF衍生物家族最后一个未开发的分子BEDO-TSeF，并阐明了其基本结构和电子基本性质。较少的

项目成果

Uniaxial strain study of electronic and crystal structures of organic conductors

有机导体电子和晶体结构的单轴应变研究

• 发表时间: 2003
• 期刊: Synthetic Metals 133-134
• 作者: S.Kagoshima

Uniaxial Strain Effects on Transport Properties of a Supramolecular Organic Conductor θ-(DIETS)_2[Au(CN)_4]

单轴应变对超分子有机导体输运性质的影响 θ-(DIETS)_2[Au(CN)_4]

• 发表时间: 2003
• 期刊: J.Phys.Soc.Jpn 72
• 作者: H.Nakagawa;K.Obara;H.Yano;O.Ishikawa;T.Hata;Naoya Tajima
• 通讯作者: Naoya Tajima

Synthesis and properties of hetero-halogenated TTFs

异卤代TTF的合成及性能

• 发表时间: 2003
• 期刊: Org.Biomol.Chem 1
• 作者: Rie Suizu

Transport properties of a Mott insulator κ-(ET)_2Cu_2(CN)_3 under the uniaxial strain

单轴应变下莫特绝缘体κ-(ET)_2Cu_2(CN)_3的输运特性

• 发表时间: 2003
• 期刊: Synthetic Metals 133-134
• 作者: Y.Kawaguchi;T.Ohmi;Y.Shimizu
• 通讯作者: Y.Shimizu

Uniaxial strain study of κ-(BEDT-TTF)_2Cu(NCS)_2

κ-(BEDT-TTF)_2Cu(NCS)_2的单轴应变研究

• 发表时间: 2003
• 期刊: Synthetic Metals 133-134
• 作者: Ishizaka;J.;A.Wakamatsu;T.Matsuno;M.Shimizu;A.Nishina;H.Ichikawa;Y.S.Suh;T.Ishikawa
• 通讯作者: T.Ishikawa