Photoinduced Persistent Polarization Change in a Spin Transition Crystal
Photoinduced Persistent Polarization Change in a Spin Transition Crystal
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DOI：
10.1002/anie.202208771
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发表时间：
2022-08-18
影响因子：
16.6
通讯作者：
Sato, Osamu
中科院分区：
文献类型：
--
作者：
Su, Sheng-Qun;Wu, Shu-Qi;Sato, Osamu
利用光作为局部热源诱导产生瞬态热释电电流被广泛认为是控制晶体材料极化的有效方法。相比之下，利用光直接调制晶体的偏振通过激发电子带仍然较少探索。在这项研究中，我们报告了铁-II自旋交叉晶体，表现出光致宏观偏振变化后，激发绿色光。当被激发的晶体弛豫到基态时，可以检测到相应的热释电电流。通过对配合物的结构、磁性、穆斯堡尔谱和红外光谱的分析，并结合计算，揭示了配合物的极化变化是由自旋跃迁过程中离子的定向相对运动决定的。自旋跃迁和极化变化在光的刺激下同时发生，这表明极性自旋交叉系统在光电材料领域的巨大潜力。
Using light as a local heat source to induce a temporary pyroelectric current is widely recognized as an effective way to control the polarization of crystalline materials. In contrast, harnessing light directly to modulate the polarization of a crystal via excitation of the electronic bands remains less explored. In this study, we report an Fe-II spin crossover crystal that exhibits photoinduced macroscopic polarization change upon excitation by green light. When the excited crystal relaxes to the ground state, the corresponding pyroelectric current can be detected. An analysis of the structures, magnetic properties and the Mossbauer and infrared spectra of the complex, supported by calculations, revealed that the polarization change is dictated by the directional relative movement of ions during the spin transition process. The spin transition and polarization change occur simultaneously in response to light stimulus, which demonstrates the enormous potential of polar spin crossover systems in the field of optoelectronic materials.