Session: Inorganic Spectroscopy:

Hard X-ray absorption spectroscopy (XAS) is a popular method for assessing electronic properties and structural features in a wide range of functional energy materials. XAS can be used to directly assess oxidation state, local geometry, and bond distances to the surrounding neighbors with element specificity and sub-angstrom precision. X-ray emission spectroscopy (XES) is a complementary tool to XAS, which characterizes the intensity distributions of the emitted x-rays and provides an additional insight into ligation state, covalency, and spin of the analytes. Combination of both spectroscopies can be used to perform the high energy resolution fluorescence detection (HERFD) XAS, which yields XAS spectra with sharpened features and higher sensitivity to small, yet relevant, chemical shifts, owing to removal of core-hole broadening. By performing full mapping of XAS and XES in resonant case, one can measure a Resonant Inelastic X-ray Scattering (RIXS) plane delivering deep insights into the target material’s electronic properties. Rich information content from combined XAS/XES experiments can help building mechanistic understanding of dynamic processes across multiple disciplines including catalysis, chemical synthesis, electrochemistry, and more. Overall, the potential of XAS and XES has a great promise in delivering new insights in material property investigations, especially in the context in situ and operando studies.

Here we demonstrate the progress in implementation of these advanced spectroscopic tools at the Inner Shell Spectroscopy (ISS) beamline at the National Synchrotron Light Source II. The current state of the single-analyzer X-ray emission spectrometer is discussed. We show the first results from the setup on ex situ samples, as well as the efforts in combination of the HERFD spectroscopy with in situ electrochemical experiments. An overview of the mechanics for the 5-analyzer setup under construction is presented.

Eli Stavitski

Appearances