Site specific chemical state analysis using anomalous scattering

该项目的目的是利用x射线的异常散射发展特定地点的化学状态分析。采用能量可调同步辐射，测量了粉末样品的x射线衍射（XRD）光谱，并将其作为x射线能量和衍射角的函数。我们修改了由Izumi博士编写的Rietvelt分析软件，并使该软件能够从XRD光谱中提取特定位置感兴趣的元素的异常散射因子。利用该软件对CO_2O_4和Fe_3O_4的异常散射因素进行了研究。得到的异常散射因子的x射线能量依赖性显示了晶体中两个不同位置的化学状态的差异。结果表明，所建立的分析方法对各种材料都是可行的。

The aim of the project is to develop site specific chemical state analysis using anomalous scattering of x-rays. Employing energy tunable synchrotron radiation, X-ray diffraction (XRD) spectra were measured from powder samples as a function of x-ray energy and diffraction angle. We have modified software for Rietvelt analysis coded by Dr. Izumi, and have enabled the software to extract anomalous scattering factor of an element of interest in a specific site from an XRD spectrum. Utilizing this software, anomalous scattering factors of CO_2O_4 and Fe_3O_4 were investigated. X-ray energy dependence of the obtained anomalous scattering factor showed difference of chemical state between two different sites in the crystal.The results show feasibility of the developed analytical method for various materials.