Time-resolved X-ray diffractometry of organic crystals by using synchrotron radiation

我们在SPring-8同步辐射装置上研制了快速时间分辨X射线衍射系统。利用时间分辨测量系统研究了脉冲激光辐照下光致变色单晶的晶格响应。下面描述关于半导体晶体的皮秒时间分辨衍射术的演示（1）和二芳基乙烯单晶的晶格响应的观察（2）所获得的结果的细节。（一）.利用同步辐射脉冲时间结构，研制了多通道定标抽运-探测时间分辨X射线衍射测量系统。三重晶体X射线衍射（TCD）已被应用到时间分辨测量系统，以确定晶格响应沿着一个特定的轴，区别于其他组件的变形。在时间分辨TCD中，单色X射线束被晶体样品衍射，并且X射线束的角 关于我们 在检测之前使用附加的单晶分析衍射光束。我们已经证明了时间分辨TCD检测声脉冲和回声的动态晶格应变在半导体晶体硅和砷化镓。（二）、二芳基乙烯的光致变色晶体在紫外光照射下变蓝，在可见光照射下恢复为原来的无色晶体。用MCS成功地测量了衍射强度随时间的变化，方法是用400 nm和633 nm的激光交替照射改变颜色。结果表明，晶体在辐照过程中发生膨胀，在辐照间隔冷却后，晶体保持剪应变或局部转动以及膨胀变化。结合使用50 μ m宽X射线狭缝的空间分辨X射线衍射测量方法，在照射侧表面周围观察到响应时间为几μs的局部应变。少

We have developed fast time-resolved X-ray diffraction system at the SPring-8 synchrotron radiation facility. The lattice response of a photochromic single crystal induced by pulsed laser irradiation has been investigated using the time-resolved measurement system. The details of the obtained results on the demonstration of picosecond time-resolved diffractometry for semiconductor crystals (1) and the observation of lattice response of a diarhylethene single crystal (2) are described below.(1). Time-resolved X-ray diffraction measurement system with multi-channel scaling (MCS) and pump-probe method using the pulsed time-structure of synchrotron radiation has been developed. Triple crystal X-ray diffractometry (TCD) has been applied to the time-resolved measurement system to determine the lattice response along a specific axis in distinction from the other components of deformation. In the time-resolved TCD, a monochromatic X-ray beam is diffracted by a crystal sample, and the angle of … More the diffracted beam is analyzed using the additional single crystal before detection. We have demonstrated the time-resolved TCD to detect acoustic pulses and the echoes as dynamical lattice strain at semiconductor crystals of silicon and gallium arsenide.(2). A photochromic crystal of diarhylethene turns blue by UV light irradiation, and is recovered to be original colorless crystal by visible light illumination. The time-evolution of the diffraction intensity has successfully been measured with the MCS by changing the color with alternate irradiation by the lasers of 400 nm and 633 nm. The results showed that the crystal expands during irradiation, and that the shear strain or local rotation as well as dilational change is kept after cooled-down at the interval of irradiations. In combination with space-resolved X-ray diffraction measurement method using an X-ray slit of 50 μm-width, local strain with a response time of a few μs has been observed around the surface on the illumination side. Less