X-RAY STUDY OF THE DENSITY WAVE INSTABILITY OF α-(BEDT-TTF)2MHg(SCN)4 with M=K and Rb
X-RAY STUDY OF THE DENSITY WAVE INSTABILITY OF α-(BEDT-TTF)2MHg(SCN)4 with M=K and Rb
复制标题
M=K和Rb的α-(BEDT-TTF)2MHg(SCN)4密度波不稳定性的X射线研究
DOI：
10.1016/s0379-6779(02)01005-6
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发表时间：
2003
期刊：
影响因子：
4.4
通讯作者：
H. Muller
中科院分区：
文献类型：
--
作者：
P. Foury;S. Ravy;J. Pouget;H. Muller
我们提出了准二维导体 a-(BEDTTTF)2MHg(SCN) 的 X 射线衍射研究，其中 M=K 和 Rb。它们分别在 TDW=8-10K 和 12-13K 处表现出密度波型相变，这通过磁阻、比热、NMR 和霍尔常数测量得到证明。结构研究表明，在环境温度下就已经存在卫星反射。相关调制与多重谐波不相称。对于某些研究的化合物，卫星反射的强度在低于 TDW 时急剧增加。根据费米面（FS）计算，结构调制的波矢实现了全局FS的良好嵌套。这表明调制与电子自由度的耦合导致电荷密度波基态。
We present an X-ray diffraction study of the quasi-2D conductors a-(BEDTTTF)2MHg(SCN), with M=K and Rb. They exhibit a phase transition of the density wave type at TDW=8-10K and 12-13K respectively, evidenced by magnetoresistivity, specific heat, NMR and Hall constant measurements. The structural study shows the presence of satellite reflections already at ambient temperature. The related modulation is incommensurate with multiple harmonics. For some of the compounds studied, the intensity of the satellite reflections strongly increases below TDW. According to Fermi surface (FS) calculations, the wave vector of the structural modulation achieves a quite good nesting of the global FS. This suggests a coupling of the modulation with the electronic degrees of freedom leading to a charge density wave ground state.