Studying modifications and reactions in materials by simultaneous Raman and X-ray powder diffraction at non-ambient conditions: methods and applications

X-ray powder diffraction played a key role in materials science over the past 25 years. It is now possible to employ powder diffraction at in situ conditions to study solid-state transformations. Real materials science samples often show deviations from the perfectly crystalline state and hence powder diffraction reaches its limits. Spectroscopic techniques can often provide useful complementary information. With the aim of gaining information from this aspect, we combined Raman spectroscopy with diffraction. A novel experimental setup for simultaneous in situ Raman and XRPD experiments was designed and realized at the SNBL line at ESRF Synchrotron (Grenoble-F). High-resolution XRPD data can be collected with a time resolution in the range of minutes. A permanently installed Raman spectrometer can now be used to measure the same sample at the same spot under the same conditions. A wide variety of non-ambient conditions are available. The setup is described with limitations and potentialities, by describing one example of application. Finally some hints on future improvements are described.