Laser-induced ferroelectric structural order in an organic charge-transfer crystal
Laser-induced ferroelectric structural order in an organic charge-transfer crystal
复制标题
DOI：
10.1126/science.1082001
复制
发表时间：
2003-04-25
期刊：
影响因子：
56.9
通讯作者：
Techert, S
中科院分区：
文献类型：
--
作者：
Collet, E;Lemée-Cailleau, MH;Techert, S
我们报道了用单色100皮秒同步辐射脉冲通过x射线衍射直接观察到的光致顺电-铁电结构相变。它发生在四硫富瓦烯-对氯醌中，四硫富瓦烯-对氯醌是一种电荷转移分子材料，其中电子和结构变化强烈耦合。一个300飞秒的激光脉冲在500皮秒的时间尺度上将材料从中性状态切换到离子状态，并且凭借固有的协同性，产生自组织的长程结构有序。X-射线数据表明激光照射后的宏观铁电重组。激光照射前后结构的细化表明分子水平上的结构变化。
We report the direct observation by x-ray diffraction of a photoinduced paraelectric-to-ferroelectric structural phase transition using monochromatic 100-picosecond synchrotron pulses. It occurs in tetrathiafulvalene-p-chloranil, a charge-transfer molecular material in which electronic and structural changes are strongly coupled. An optical 300-femtosecond laser pulse switches the material from a neutral to an ionic state on a 500-picosecond time scale and, by virtue of intrinsic cooperativity, generates self-organized long-range structural order. The x-ray data indicate a macroscopic ferroelectric reorganization after the laser irradiation. Refinement of the structures before and after laser irradiation indicates structural changes at the molecular level.