Measurement of Anomalous Scattering Facotor near Absorption Edge by Pendellosung Beat

实际晶体中的异常散射因子与基于吸收边附近自由原子模型的理论计算结果不同，从而影响固体的成键效果。现在，还没有足够的实验数据。我们发现反常散射因子的变化会引起Pendellosung拍（PBXRS），PBXRS可以准确地测定吸收边附近的反常散射因子。在本研究中，我们利用半导体样品和纤丝样品测量了光子晶体的X射线吸收光谱，得到了吸收边附近的反常散射因子。在实验前，我们用动力学理论考察了衍射条件，包括了在PBXRS中可以观察到的吸收效应。在KEK-PF的BL 6C 1上使用同步辐射和SSD四圆衍射仪进行了实验。此外，还使用了测量系统和小型旋转衍射仪（最小设置角0.02秒）。设置在四圆衍射仪的phi轴上。样品是在500 cm 2内为EPO的GaAs，<-2>并且在平行板型上加工。通过在Ga K吸收边附近的0.42 eV的能量阶跃测量了200反射的PBXRS。用剖面拟合法由实测数据求出了反常散射因子。在本研究中，Ga（f '_）反常散射因子的真实的普拉<Ga>在吸收边以下50 eV处比Parratt和Hempstead方法的理论计算值小2-6%，在5 eV处比Cromer和Liberman方法的理论计算值小9-13%。

The anomalous scattering factor in the actual crvstal differs from it of the theoretical calculation based on the free atom model near the absorption edge, which affects the bonding effect of the solid. Now, there is not enough to the experimental data. We found Pendellosung beat (PBXRS) caused by the change of the anomalous scattering factor and PBXRS is possible to determine accurately the anomalous scattering factor near the absorption edge. In the study, we measure PBXRS by the semi-conductor samples and wisker samples and obtained the anomalous scattering factor near the absorption edge. Moreover, we consider the result that compare the obtained one with one of the theoretical calculation.Before the experiment, we examined the diffraction condition by the dynamical theory included the absorption effect which can be observed PBXRS fine. The experiment performed to use the synchrotron radiation and the four-circle diffractometer with SSD set on BL6C1 in KEK-PF.Further, these used the measuring system and the small rotating diffractmeter (minimum set angle 0.02 sec.) set on phi axis of the fourcircle diffractometer. The samples were GaAs that is EPO within 500 cm^<-2> and processed on the parallel plate type. PBXRS of 200 reflection were measured by the energy steps of 0.42 eV near Ga K-absorption edge. The anomalous scattering factor obtained from the measured data by the profile fitting method. In this study, the real prat of the anomalous scattering factor of Ga (f'_<Ga>) is 2-6% smaller at 50 eV below the absorption edge and 9-13% smaller at 5 eV than ones of the theoretical calculation by Parratt and Hempstead's method and by Cromer and Liberman's method, respectively.