A new stages of the anisotropic extension for the fragile molecular solids, the charge ordering and the superconducting transition

脆性分子固体各向异性扩展、电荷有序和超导转变的新阶段

• 批准号: 20850024
• 负责人: YAMAMOTO Takashi
• 金额: $ 2.1万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (Start-up)
• 财政年份: 2008
• 资助国家: 日本
• 起止时间: 2008 至 2009
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-20850024/
• 关键词: 分子凝縮体; 延伸下物性測定法; 特殊環境下に対応した材料開発; 超伝導機構; 電荷整列; スピンフラストレーション; 分子内振動; 電荷揺らぎの相分離; 分子性固体; 伝導性; 磁性; 延伸下物性

(1) In the field of condensed molecular solids, the anisotropic extension is the new method exploring the notable phase transition. In the previous study, we have developed the methodology observing the temperature dependence of the electrical resistivity under the anisotropic extension and the magnetic field. As a next step, the measurement of the magnetic susceptibility has been tried. The epoxy resin often used for the low temperature physics is not appropriate for our purpose because of the chemical reaction with the sample crystal. The chemical reaction can be avoided by using another kind of resin for sample coating. Nevertheless, we find that this method is not suitable for the magnetic susceptibility measurement, because the sample is separated from the epoxy rod when the extension is applied to the epoxy rod. We have started from examining the resin which is free from chemical reaction and sample coating. We have found that the resin made from some chemicals satisfies above re … More quirements. By using above resin and sample crystals, the temperature dependence of the magnetic susceptibility was successfully measured.(2) The conducting molecular solids are roughly classified into two groups from the viewpoint of the structures of two-dimensional layer. In one group, two-dimensional layer consists of a tight dimer. In the other group, a loose dimer contributes to the two-dimensional layer. As for the former group, the role of charge and lattice have not been examined so far whereas the magnetic interaction is intensively studied. A series of [Pd(dmit)_2]_2X is a good model compound because not only anti-ferromagnetic state, characteristic of the tight dimer syatem, but also non-magnetic insulator state. We have developed the methodology evaluating the roles of charge and lattice in [Pd(dmit)_2]_2X using vibrational spectroscopy. After confirmation of the methodology, we have applied thevibrational spectroscopy to the some materials exhibiting the spin-liquid behavior and the phase transition from non-magnetic insulator to superconducting state. We have found that the electron-electron interaction and the electron-phonon interaction play an important roles in the physical properties of above materials. We have also observed vibrational spectra of the K?type ET salt exhibiting the spin-frustration. The experimental results strongly suggest the important role of the electron-electron interaction and the electron-phonon interaction in the ground state. These observations imply that the conducting and magnetic properties for both tight dimer and loose dimer materials can be understood from the generalized mechanism."(3) The charge ordered transition requires the inter-molecular Coulomb interaction and an additional interaction. In the previous study, we have shown that the secondary strong Coulomb interaction and the electron-phonon interaction become an additional interaction. In order to explore other additional interaction, we have examined the role of the hydrogen bond using the molecular conductor containing an amide-group, which is synthesized by Prof. Batail's group. Applying the vibrational spectroscopy to the present material, we have found that the anti-ferromagnetic state is the charge ordering state. The observed spectra indicates the hydrogen bond can participate in the phase transition. Less

(1)在凝聚态分子固体领域，各向异性延伸是探索显着相变的新方法。在前期研究中，我们发展了观察各向异性延伸和磁场下电阻率随温度变化的方法。下一步，我们尝试了磁化率的测量，因为它会与样品晶体发生化学反应，因此通常用于低温物理的环氧树脂不适合我们的目的。可以通过使用另一种材料来避免。种类然而，我们发现这种方法不适合磁化率测量，因为当将延伸件施加到环氧树脂棒上时，样品与环氧树脂棒分离。我们发现由某些化学品制成的树脂满足上述要求。通过使用上述树脂和样品晶体，成功地测量了磁化率的温度依赖性。（2）导电分子。从二维层结构的角度来看，固体大致分为两类：一类是紧密二聚体，另一类是松散二聚体。对于前一组，电荷和晶格的作用尚未得到研究，而一系列[Pd(dmit)_2]_2X是一个很好的模型化合物，因为它不仅具有反铁磁态，而且具有特征。的我们开发了使用振动光谱评估电荷和晶格在[Pd(dmit)_2]_2X中的作用的方法。在方法确认后，我们将振动光谱应用于。我们发现一些材料表现出自旋液体行为和从非磁性绝缘体到超导态的相变。电子-声子相互作用在上述材料的物理性质中发挥着重要作用，我们还观察到了表现出自旋挫败的K型ET盐的振动光谱，实验结果有力地表明了电子-电子相互作用的重要作用。这些观察结果表明，紧密二聚体和松散二聚体材料的导电和磁性都可以从广义机制来理解。”(3) 电荷有序跃迁需要分子间库仑相互作用。和在之前的研究中，我们已经证明了二次强库仑相互作用和电子-声子相互作用成为一种附加相互作用，为了探索其他附加相互作用，我们使用分子导体研究了氢键的作用。 Batail教授团队合成的含有酰胺基团的材料，将振动光谱应用于该材料，发现反铁磁态是电荷有序态。观察到的光谱表明氢键可以参与。相变较少。

项目成果

Low temperature heat capacity measurements of the spin-liquid states of hydrogenerated and deuteratedκ-(BEDT-TTF)2Cu2(CN)3

氢化和氘化κ-(BEDT-TTF)2Cu2(CN)3自旋液体态的低温热容测量

• 发表时间: 2010
• 期刊: Physica B Vol.405
• 作者: S. Yamashita;T. Yamamoto;et. al
• 通讯作者: et. al

Infrared and Raman Study of the Charge-Ordered State in the Vicinity of the Superconducting State in the Organic Conductor β-(meso-DMBEDT-TTF)_2PF_6

有机导体β-(meso-DMBEDT-TTF)_2PF_6超导态附近电荷有序态的红外和拉曼研究

• 发表时间: 2008
• 期刊: Journal of the Physical Society of Japan 77(2)
• 作者: K. -Y. Song;K. S. Abedin;and K. Hotate;吉田久美;M. Tanaka
• 通讯作者: M. Tanaka

固体物理、トピックス欄「分子性導体の電荷整列」

固体物理，主题部分“分子导体中的电荷排列”

• 发表时间: 2009
• 作者: 山本貴;など
• 通讯作者: など

多様な基底状態を取る[Pd(dmit)2]塩の分光学的研究

不同基态[Pd(dmit)2]盐的光谱研究

• 发表时间: 2008
• 作者: 山本貴;等
• 通讯作者: 等

水素結合由来の構造揺らぎ持つ有機固体における磁気秩序と電荷秩序

具有源自氢键的结构涨落的有机固体中的磁序和电荷序

• 发表时间: 2009
• 作者: 山本貴;等
• 通讯作者: 等