Simultaneous quick-scanning X-ray absorption spectroscopy and X-ray diffraction

Abstract

The existing setup for time-resolved quick-scanning X-ray absorption spectroscopy (QEXAFS) at beamline P64 at the PETRA III storage ring is complemented by new infrastructure suited for the collection of X-ray diffraction data simultaneously to the QEXAFS experiment. In particular, the sinusoidal periodic movements of the quick-EXAFS mono-chromator are modified in such a way, that an energy plateau with approximately constant energy over a certain time is created in the pre-edge region of the absorption edge of interest. By employing a properly defined trigger signal in this time, the exposure of a two-dimensional X-ray detector placed behind the sample is actuated, thus allowing to collect an X-ray diffraction pattern over a certain angular range as defined by the actual X-ray energy and the position of the 2D-detector. Details of the new setup as well as exemplary results obtained during the solvothermal synthesis of ZnO nanoparticles and the bcc-fcc phase transition of iron at elevated temperatures are presented.