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

点击翻译按钮获取中文摘要

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.