Investigation of X-ray diffuse scattering in θ-(BEDT-TTF) 2RbM'(SCN)4
Investigation of X-ray diffuse scattering in θ-(BEDT-TTF) 2RbM'(SCN)4
复制标题
θ-(BEDT-TTF) 2RbM(SCN)4 中 X 射线漫散射的研究
DOI：
10.1016/s0379-6779(02)00769-5
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发表时间：
2003
期刊：
影响因子：
4.4
通讯作者：
H. Mori
中科院分区：
文献类型：
--
作者：
M. Watanabe;Y. Noda;Y. Nogami;H. Mori
用X射线衍射方法研究了θ-（BEDT-TTF）2 RbM '（SCN）4;（M'= Zn、Co）的调制结构。θ-（BEDT-TTF）2 RbM '（SCN）4是一种二维有机导体，在210 K时表现出金属-绝缘体转变。绝缘相被称为电荷有序态。在TMI = 210 K以上，出现了q=（1/3 k1/4）的扩散棒，在TMI以下，随样品冷却速度的不同，扩散棒的大小也有一定的差异。在慢冷态（0.2 K/min），q=（1/3 k 1/4）的扩散棒消失，取而代之的是c*/2的超晶格。在快速冷却状态（5-6 K/min）下，在T_I处的结构相变变得不完美。q的扩散棒保持在TMI以下，c*/2的晶格调制在导电层间方向上无序。
The modulated structure of θ-(BEDT-TTF) 2 RbM'(SCN) 4;(M'= Zn, Co) were investigated by X-ray diffraction method. θ-(BEDT-TTF) 2 RbM'(SCN) 4 are two-dimensional organic conductors which exhibit metal-insulator transition at 210 K. The insulating phase is known as a charge ordered state. Above T MI= 210 K, diffuse rod of q=(1/3 k 1/4) was found. Below T MI, there are some differences depending on the sample cooling speed. In the slow-cooled-state (0.2 K/min), the diffuse rod of q=(1/3 k 1/4) disappears and is replaced by superlattice of c*/2. In the rapid-cooled-state (5-6 K/min), the structural phase transition at T I becomes imperfect. The diffuse rod of q remains below TMI and the lattice modulation of c*/2 is disordered in the direction of inter-conducting-layer.