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

一维有机导体连续 SDW 跃迁中电子态的研究

• 批准号: 13640375
• 负责人: NAKAMURA Toshikazu
• 金额: $ 2.05万
• 依托单位: Okazaki National Research Institutes
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640375/
• 关键词: Organic Conductors; NMR; ESR; SDW; Charge Order; 電荷秩序

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.

在本计画中，我们进行了微观研究，以厘清一维有机导体的低温电子态。（EDT-TTF）_2AuBr_2是一维1/4填充体系。我们进行了SQUID，EPR和1H-NMR测量。我们发现（EDT-TTF）_2AuBr_2在16 K发生了SDW跃迁。我们观察到磁相的核磁共振自旋-晶格弛豫速率的异常第二峰，表明连续的SDW相变。而且。1H-NMR谱线的形状随第二相变而变化。我们对一系列一维有机导体（TMTTF）2X进行了磁共振研究。我们发现，（TMTTF）2X盐大致分为三组根据ESR线宽在低温下的各向异性。我们总结了它们的起源，由于三种类型的电荷配置。我们还对典型的（TMTTF）2X盐进行了13 C NMR研究。在（TMTTF）2SCN中，我们发现了反常的自旋弛豫过程。阴离子有序化和4kF CDW之间可能存在竞争。

项目成果

T.NAKAMURA: "ESR study of the charge ordering in (TMTTF)_2X"Physica B.. 329-333. 1148-1149 (2003)

T.NAKAMURA：“(TMTTF)_2X 中电荷排序的 ESR 研究”Physica B.. 329-333。

T.NAKAMURA: "Observation of SDW Sub-Phasein Q1D 1/4-Filled System, (EDT-TTF)2AuBr2"Synth.Met.. 120. 831 (2001)

T.NAKAMURA：“SDW 子阶段 Q1D 1/4 填充系统的观察，(EDT-TTF)2AuBr2”Synth.Met.. 120. 831 (2001)

T.NAKAMURA: "Possible Charge Ordering Patterns of the Paramagnetic Insulating States in (TMTTF)2X"J.Phys.Soc.Jpn.. 72. 213-216 (2003)

T.NAKAMURA：“(TMTTF)2X 中顺磁绝缘态的可能电荷排序模式”J.Phys.Soc.Jpn.. 72. 213-216 (2003)

T.NAKAMURA, K.MAEDA: "Competition Electronic States of (TMTTF)2MF6: ESR Investigations"J.Phys.IV France. (in press).

T.NAKAMURA、K.MAEDA：“(TMTTF)2MF6 的竞争电子态：ESR 调查”J.Phys.IV 法国。

S.Fujiyama, T.Nakamura: "NMR Investigation of (TMTTF)_2X : Charge Configurations and Spin Dynamics"Synth.Met.. 133-134. 67-68 (2003)

S.Fujiyama、T.Nakamura：“(TMTTF)_2X 的 NMR 研究：电荷构型和自旋动力学”Synth.Met.. 133-134。