Investigation of the electronic states in the successive SDW transitions of one-dimensional organic conductors

在这个项目中，我们进行了微观研究，以澄清一维有机导体的低温电子态。（EDT-TTF）2AuBr2为一维1/4填充体系。我们进行了SQUID， EPR和1H-NMR测量。我们发现（EDT-TTF）2AuBr2在16K时发生SDW跃迁。我们观察到磁相中核磁共振自旋晶格弛豫率的异常第二峰，表明连续的SDW相变。此外。h - nmr谱线形状随第二相转变而变化。连续的SDW相变的起源很可能是磁结构的重建。对一系列一维有机导体（TMTTF）2X进行了磁共振研究。根据ESR线宽的各向异性，我们发现（TMTTF）2X盐在低温下大致分为三组。我们根据这三种电荷构型推断出它们的来源。我们还对典型的（TMTTF）2X盐进行了13C核磁共振研究。在（TMTTF）2SCN中，我们发现了异常的自旋弛豫过程。阴离子排序和4kF CDW之间可能存在竞争。

In this project, we performed the microscopic investigation to clarify the low temperature electronic states of one-dimensional organic conductors.(EDT-TTF)2AuBr2 is a one-dimensional 1/4-filled system. We carried out SQUID, EPR, and 1H-NMR measurements. We found that(EDT-TTF)2AuBr2 which undergoes an SDW transition at 16K. We observed an anomalous second-peak of the NMR spin-lattice relaxation rate in the magnetic phase, indicating a successive SDW phase transitions. Moreover. the 1H-NMR line shape changes with the second phase transition. It is likely that the origin of the successive SDW phase transitions is a reconstruction of the magnetic structure.Magnetic resonance investigations were performed for a series of one-dimensional organic conductors, (TMTTF)2X. We found that the (TMTTF)2X salts are roughly divided into three groups according to the anisotropy of the ESR linewidth at low temperatures. We concluded their origins due to the three types of charge configurations. We also performed 13C NMR study for typical (TMTTF)2X salts. In (TMTTF)2SCN, we found anomalous spin relaxation process. Possible competition between the anion ordering and 4kF CDW is likely.