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

(1)在凝聚态分子固体领域，各向异性扩展是探索显著相变的新方法。在前人的研究中，我们发展了观察各向异性延伸和磁场作用下电阻率与温度关系的方法。下一步，尝试了磁化率的测量。通常用于低温物理的环氧树脂由于与样品晶体发生化学反应而不适合我们的目的。用另一种树脂涂覆样品可以避免化学反应。然而，我们发现这种方法不适合磁化率的测量，因为当环氧棒上施加延伸时，样品会与环氧棒分离。我们从检查无化学反应的树脂和样品涂层开始。我们发现，由一些化学品制成的树脂满足以上要求。利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)从二维层结构的角度将导电分子固体大致分为两类。在一组中，二维层由紧密二聚体组成。在另一组中，松散的二聚体有助于形成二维层。对于前者，电荷和晶格的作用尚未得到研究，而磁相互作用则得到了深入的研究。[Pd(dmit)_2]_2X系列化合物既具有紧二聚体体系的反铁磁性，又具有非磁性绝缘体状态，是一种很好的模型化合物。我们发展了用振动光谱评价电荷和晶格在[Pd(dmit)_2]_2X中的作用的方法。在验证了方法之后，我们将振动光谱应用于一些表现自旋液体行为和从非磁性绝缘体到超导态相变的材料。我们发现电子-电子相互作用和电子-声子相互作用对上述材料的物理性质起着重要的作用。我们还观察到了K？ET型盐表现出自旋受挫。实验结果有力地说明了电子-电子相互作用和电子-声子相互作用在基态中的重要作用。这些观察结果表明，紧二聚体和松散二聚体材料的导电性和磁性都可以从广义机理来理解。(3)电荷有序跃迁需要分子间的库仑相互作用和一个附加的相互作用。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-声子相互作用成为附加的相互作用。为了探索其他额外的相互作用，我们使用含有酰胺基团的分子导体来研究氢键的作用，这是由Batail教授的团队合成的。将振动光谱应用于该材料，我们发现反铁磁态是电荷有序态。观察到的光谱表明，氢键参与了相变。少

(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