DEVELOPMENT OF HIGH TEMPERATURE ORGANIC SUPERCONDUCTORS

高温有机超导体的开发

• 批准号: 63060004
• 负责人: IKEMOTO Isao
• 金额: $ 162.56万
• 依托单位: TOKYO METROPOLITAN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Specially Promoted Research
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63060004/
• 关键词: Organic Superconductors; radical salt; BEDT-TTF; DMET; unsymmetrical electron donor; conductivity; isotope effect; fullerene; BEDTーTTF; 相転移; 相移転

1)To develop new superconductors,we investigated mainly on the derivative molecules of an unsymmetrical donor DMET;DMPT,DMMT,DIMET and ETDM.DMPT and DMMT are the derivatives with different side-bones from DMET,and DIMET and ETDM have the same backbone to that of DMET,but a different arrangement of hetero-atoms from that of DMET.Several radical salts of DIMET and ETDM show a metallic behavior at low temperature,so there remains the possibilities that the superconductors based on DIMET or ETDM will be discovered.2)The fullerene superconductors are also studied. C_<60>M_3 was found to have a transition from metallic phase to a superconducting phase. The doping method with metal azide produced the material (C_<60>K_2Cs_1) which had 100% superconducting volume,so this method was clarified to be efficient for making a good fullerene superconductor. We obtained more reliable coherent lengths for C_<60> superconductors by the aid of the renormalization theory.3)In the case of BEDT-TTF salts,we … More discovered five superconductors; kappa-(BEDT-TTF)_2Cu(NCS)_2(Tc=10.4K), kappa'-(BEDT-TTF)_2Cu_2(CN)_3(Tc=3.8K), kappa-(BEDT-TTF)_2Cu(CN)[N(CN)_2](Tc=11.2K), alpha-(BEDT-TTF)_2NH_4(SCN)_4(Tc=0.8K), alpha-(BEDT-TTF)_2KHg(SCN)_4(Tc=0.1-0.2K). In addition, we observed a new superconducting phase (Tc=2k) in beta(BEDT-TTF)_2I_3. In these salts we studied the isotropic effect on Tc, substituting the CH_2 groups of the donor molecules by ^<13>CH_2 and by CD_2. The deuterated salt of kappa-(BEDT-TTF)_2Cu(CN)[N(CN)_2] recorded the highest Tc(12.3K)among the ambient pressure TTF-based organic superconductors.In the process of this investigation we proposed a molecular and crystal designing for superconductor.Namely,"big and thin anion which forms two-dimensional anion layer gives the high Tc salts."We have also derived a new molecular and crystal design by finding the structural correlations between the opening of the anion layer and the donor packing pattern and the one between Tc and the conduction volume of the donor layer.Employing not only BEDT-TTF but also newly prepared donor molecules,we have obtained the new superconductors and a number of metallic salts down to liquid He temperature.Further research for the high Tc organic superconductors is currently under way. Less

1）为了开发新的超导体，我们主要研究了非对称给体DMET的衍生物分子; DMPT、DMMT、DIMET和ETDM.DMPT和DMMT是DMET的不同侧链衍生物，DIMET和ETDM与DMET具有相同的主链，但杂原子的排列与DMET不同. DIMET和ETDM的几种自由基盐在低温下表现出金属性，2）对富勒烯超导体也进行了研究。发现C_<60>M_3有从金属相到超导相的转变。用金属叠氮化物掺杂的方法制备了具有100%超导体积的材料（C_K_2Cs_1<60>），说明这种方法是制备良好的富勒烯超导体的有效方法。3<60>）在BEDT-TTF盐的情况下，我们利用重整化理论计算了C_（10）超导体的相干长度 ...更多信息 发现了五种超导体; Kappa-（BEDT-TTF）_2Cu（NCS）_2（Tc=10.4K）、Kappa'-（BEDT-TTF）_2Cu_2（CN）_3（Tc=3.8K）、Kappa-（BEDT-TTF）_2Cu（CN）[N（CN）_2]（Tc=11.2K）、α-（BEDT-TTF）_2NH_4（SCN）_4（Tc=0.8K）、α-（BEDT-TTF）_2KHg（SCN）_4（Tc=0.1-0.2K）。此外，在β（BEDT-TTF）_2I_3中还观察到一个新的超导相（Tc=2k）。在这些盐中，我们研究了各向同性效应对Tc的影响，用^ CH_2和CD_2取代供体分子的CH_2基团<13>。在常压下，Kappa-（BEDT-TTF）_2Cu（CN）[N（CN）_2]的氘代盐具有最高的Tc（12.3K）。在研究过程中，我们提出了一种超导体的分子和晶体设计，即“大而薄的阴离子形成二维阴离子层，得到高Tc的盐”。“我们还通过发现阴离子层的开口与施主堆积模式之间的结构相关性以及Tc与施主层的传导体积之间的结构相关性，导出了一种新的分子和晶体设计。不仅使用BEDT-TTF，而且使用新制备的施主分子，我们已经获得了新的超导体和一些低至液态He温度的金属盐。对高Tc有机超导体的进一步研究是目前正在进行中。少

项目成果

T.Osada: "Commensurability Effect of Magnetoresistance Anisotropy in a Quasi-One-Dimensional Conductor Tetramethyltetraselenafulvalenium Perchlorate (TMTSF) _2ClO_4" Phys.Rev.Lett.66. 1525-1528 (1991)

T.Osada：“准一维导体四甲基四硒富瓦烯高氯酸盐 (TMTSF) _2ClO_4 中磁阻各向异性的可通约性效应”Phys.Rev.Lett.66。

Y.Iwasa: "Temperature Induced NeutralーIonic Transition in TetramethylbenzidineーTetracyanoquinodimethane" Phys.Rev.B42. 2374-2377 (1990)

Y.Iwasa：“四甲基联苯胺-四氰基醌二甲烷中的温度诱导中性离子转变”Phys.Rev.B42 (1990)。

Y.Iwasa,G.saito and S.Kagoshima Eds.: "Dynamics of Charged Domain Walls in Semiconducting Charge Transfer Compounds" Springer Prodeedings in Physics 51.The Phisycs and Chemistry of Organic Superconductors. 319-323 (1990)

Y.Iwasa、G.saito 和 S.Kagoshima 编辑：“半导体电荷转移化合物中带电畴壁的动力学”施普林格物理学报 51。有机超导体的物理和化学。

K.Oshima,G.Saito and S.Kagoshima Eds.: "Anomalous Trnasport Behavior in κー(BEDTーTTF)_2Cu(NCS)_2" Springer Prodeedings in Physics 51.The Phisycs and Chemistry of Organic Superconductors. 276-279 (1990)

K.Oshima、G.Saito 和 S.Kagoshima Eds.：“κ-(BEDT-TTF)_2Cu(NCS)_2 中的异常转运行为”施普林格物理学报 51。有机超导体的物理和化学 276-279（ 1990）

H.Mori: "Crystal and Electronic Structures of (BEDTーTTF)_2[MHg(SCN)_4](M=K and NH_4)" Bull.Chem.Soc.Jpn.63. 2183-2190 (1990)

H.Mori：“(BEDT-TTF)_2[MHg(SCN)_4](M=K 和 NH_4) 的晶体和电子结构”Bull.Chem.Soc.Jpn.63 (1990)。