In situ characterization of electrochemical systems can provide deep insights into the structure of electrodes under applied potential. Grazing‐incidence X‐ray diffraction (GIXRD) is a particularly valuable tool owing to its ability to characterize the near‐surface structure of electrodes through a layer of electrolyte, which is of paramount importance in surface‐mediated processes such as catalysis and adsorption. Corrections for the refraction that occurs as an X‐ray passes through an interface have been derived for a vacuum–material interface. In this work, a more general form of the refraction correction was developed which can be applied to buried interfaces, including liquid–solid interfaces. The correction is largest at incidence angles near the critical angle for the interface and decreases at angles larger and smaller than the critical angle. Effective optical constants are also introduced which can be used to calculate the critical angle for total external reflection at the interface. This correction is applied to GIXRD measurements of an aqueous electrolyte–Pd interface, demonstrating that the correction allows for the comparison of GIXRD measurements at multiple incidence angles. This work improves quantitative analysis of d‐spacing values from GIXRD measurements of liquid–solid systems, facilitating the connection between electrochemical behavior and structure under in situ conditions.

中文翻译：

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应用于Pd电极的原位掠入射X射线衍射研究的掩埋界面折射校正

原位电化学系统的表征可以深入了解施加电势下的电极结构。掠入射X射线衍射（GIXRD）是一种特别有价值的工具，因为它具有通过电解质层表征电极近表面结构的能力，这在表面介导的过程（如催化和吸附）中至关重要。对于真空-材料界面，已经得出了X射线穿过界面时发生的折射校正。在这项工作中，开发了一种更通用的折射校正形式，可以应用于包括液体-固体界面在内的掩埋界面。校正在接近界面的临界角的入射角处最大，而在大于或小于临界角的角处减小。还引入了有效的光学常数，可用于计算界面处全外反射的临界角。此校正应用于电解质-Pd界面的GIXRD测量，表明该校正允许在多个入射角下比较GIXRD测量。这项工作改进了对来自液固系统GIXRD测量的d间距值，有助于现场条件下电化学行为与结构之间的联系。