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

我们在SPUNG-8同步辐射装置上研制了快速时间分辨X射线衍射仪。利用时间分辨测量系统研究了脉冲激光辐照光致变色单晶的晶格响应。现给出半导体晶体(1)皮秒时间分辨衍射法演示和二芳基乙烯单晶(2)晶格响应观测的详细结果如下：(1)利用同步辐射的脉冲时间结构，研制了多通道定标泵浦探测时间分辨X射线衍射测量系统。三晶X射线衍射仪(TCD)已被应用于时间分辨测量系统，以确定沿特定轴的晶格响应，以区别于变形的其他分量。在时间分辨热像仪中，单色X射线束被晶体样品衍射，…的角度此外，在检测前利用附加的单晶对衍射光进行分析。我们已经证明了时间分辨TCD在硅和砷化镓半导体晶体中以动态晶格应变的形式探测声脉冲和回波。二芳基乙烯的光致变色晶体在紫外光照射下变为蓝色，并在可见光照射下恢复为原来的无色晶体。用400 nm和633 nm激光交替照射变色的MCS成功地测量了衍射光强度的时间演化。结果表明，晶体在辐照过程中发生膨胀，在辐照间隔降温后，晶体保持了剪切应变或局部旋转和膨胀的变化。结合50μm宽X射线狭缝的空间分辨X射线衍射测量方法，在照明面附近观察到了响应时间为几μ的局部应变S。较少

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