RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan.
Phys Rev Lett. 2013 May 31;110(22):227401. doi: 10.1103/PhysRevLett.110.227401. Epub 2013 May 28.
Photoinduced effects caused by intramolecular excitation were investigated by simultaneous optical and transport measurement in two charge-ordered organic salts, (BEDT-TTF)3X2 (X=ReO4, ClO4) [BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene]. Although the two salts have the same molecular (average) charge and arrangement, they showed different photoinduced effects. A photoinduced insulator-to-metal phase transition with a metastable charge order-melting state was observed in the ReO4 salt where the charge ordered state is associated with the lattice distortion. On the other hand, no photoinduced insulator-to-metal phase transition was noted in the ClO4 salt where the charge ordered state is not accompanied by the lattice distortion. This comparative study suggested that the lattice distortion plays a key role in the stabilization of the photoinduced phase.
通过在两个电荷有序有机盐 (BEDT-TTF)3X2 (X=ReO4, ClO4) [BEDT-TTF=双(乙基二硫代)四硫富瓦烯] 中进行同步光学和输运测量，研究了分子内激发引起的光致效应。尽管这两种盐具有相同的分子（平均）电荷和排列，但它们表现出不同的光致效应。在 ReO4 盐中观察到了一个光致绝缘到金属的相变，伴随着亚稳的电荷有序熔融状态，其中电荷有序状态与晶格畸变有关。另一方面，在 ClO4 盐中没有观察到光致绝缘到金属的相变，其中电荷有序状态不伴随晶格畸变。这项比较研究表明，晶格畸变在光致相的稳定化中起着关键作用。
