Chow DS, Zamborszky F, Alavi B, Tantillo DJ, Baur A, Merlic CA, Brown SE
Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547, USA.
Phys Rev Lett. 2000 Aug 21;85(8):1698-701. doi: 10.1103/PhysRevLett.85.1698.
Using one- and two-dimensional NMR spectroscopy applied to 13C spin-labeled (TMTTF)2AsF6 and (TMTTF)2PF6, we demonstrate the existence of an intermediate charge-ordered phase in the TMTTF family of charge-transfer salts. At ambient temperature, the spectra are characteristic of nuclei in equivalent molecules. Below a continuous charge-ordering transition temperature T(co), there is evidence for two inequivalent molecules with unequal electron densities. The absence of an associated magnetic anomaly indicates only the charge degrees of freedom are involved and the lack of evidence for a structural anomaly suggests that charge-lattice coupling is too weak to drive the transition.
通过对13C自旋标记的(TMTTF)2AsF6和(TMTTF)2PF6应用一维和二维核磁共振光谱，我们证明了电荷转移盐TMTTF家族中存在中间电荷有序相。在室温下，光谱是等效分子中原子核的特征。在连续的电荷有序转变温度T(co)以下，有证据表明存在两个具有不等电子密度的不等价分子。没有相关的磁异常表明仅涉及电荷自由度，并且缺乏结构异常的证据表明电荷-晶格耦合太弱而无法驱动转变。
