New Spectroscopy using combination of synchrotron radiation and laser

为了研究光致相变，近年来我们一直在发展基于同步辐射和激光相结合的新技术。(1)我们在KEK-PF的XAFS站建立了新的快速数据采集系统，其中可以使用来自摇摆器的强X射线。由于XAFS可以提供组分之间的局域原子距离，因此该系统对于研究光诱导的结构变化是强有力的。将该系统应用于自旋交叉络合物，得到了光致相晶体结构的新信息。(2)我们还在分子科学研究所UVSOR构建了基于同步辐射和激光的组合光电子系统。在束线BL5A和BL6A2上，用芯级光电子能谱研究了GaAs光感生表面光电压。[Fe(2-pic)3]Cl2EtOH单晶的光致相变。还用同步辐射和激光的光电子能谱进行了研究。室温下激光激发下Fe(2-pic)3]Cl2EtOH的价态UPS谱没有显示出任何变化，但它清楚地表明，从RT冷却到40K以及在40K下激光激发都使样品的价态发生了剧烈的变化。实验结果表明，光诱导相的电子结构与高自旋态的电子结构不同。(3)在京都大学生长了自旋交叉络合物的单晶，并构建了ESR和拉曼系统来研究光诱导相变。拉曼光谱结果表明，[Fe(2-pic)_3]Cl_2EtOH的光诱导相对称性降低。(4)在佐贺大学，讨论了同步辐射和激光相结合用于光诱导现象的前景。

In order to investigate the photo-induced phase transitions, we have been developing new techniques based on the combination of synchrotron radiation and laser in recent years.(1) We have constructed the new fast data acquisition system at the XAFS station of KEK-PF, where intense X-rays from a wiggler can be used. The system is powerful to investigate the photo-induced structural change since XAFS can provide the local atomic distance between the constituents. The system was applied to a spin crossover complex, resulting in the new information of the crystal structure of photo-induced phase.(2) We have also constructed the combination photoelectron system based on the synchrotron radiation and laser at UVSOR, Institute for Molecular Science. AT beam lines BL5A and BL6A2, core-level photoelectron spectroscopy was carried out to investigate the photo-induced surface photo voltage on GaAs. The photo-induced phase transition on a single crystal of [Fe(2-pic)_3] Cl_2EtOH. was also investigated with photoelectron spectroscopy using synchrotron radiation and laser. The UPS spectra of valence states of Fe(2-pic)_3] Cl_2EtOH did not show any change by laser excitation at room temperture, but it showed clearly that the valence states drastically changed by cooling the sample from RT to 40K and also by the laser-excitation at 40K. The experimental results indicate that the electronic structure of the photo-induced phase is not the same as that of the high-spin state.(3) At Kyoto university single crystals of spin crossover complexes were grown and the ESR and Raman systems were constructed to investigate the photo-induced phase transition. The Raman spectroscopy results indicated the clear evidence of the symmetry lowering in the photo-induced phase of [Fe(2-pic)_3] Cl_2EtOH.(4) AT Saga University, the future prospect of the combinational use of synchrotron radiation and laser for photo-induced phenomena was discussed.