Observation of changes in crystalline structures and electronic properties of materials during chemical reactions and phase transformations remains a challenge in materials science [1-3]. We have developed a multimodal setup to perform combined in-situ X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) measurements at the Balder beamline at MAX IV [4]. This enables us to obtain multi-dimensional information of materials and processes such as long-range crystalline order via XRD, the electronic properties via XAS and short-range correlations via extended X-ray absorption fine structure (EXAFS). The high photon flux ($\sim10^{12}$ photons/s) over a wide range of energies (4 – 40 keV) allows to investigate processes with a sub-second time-resolution. This is complemented by real-time visualization and data (pre-)analysis capabilities. The setup consists of ion-chambers and multi-element detectors for XAS measurements in transmission and fluorescence modes, respectively, and a hybrid-pixel area detector for XRD measurement. Beyond sequentially repeated XAS-XRD measurements, the developments allow for strictly simultaneous measurements, such as recording a diffraction pattern for every point in energy. This paves the way for in-situ diffraction anomalous fine structure (DAFS) [5] measurements as an inherent combination of XAS and XRD to obtain site selective electronic information. We will present the specifics of our experimental setup, the modalities of data acquisition and treatment, and a few examples of measurements, reaching from sequentially combined XAS-XRD to DAFS.

[1] W. Gruenert; K. Klementiev Physical Sciences Reviews, 2020, 5, 20170181. [2] C. Giannini et al. J.S. Smith Crystals, 2016, 6, 87.

[2] C. Giannini et al. J.S. Smith Crystals, 2016, 6, 87.

[3] L. Lukashuk; K. Foettinger Johns Matthey. Technol. Rev., 2018, 62, 316.

[4] K. Klementiev; K. Norén; S. Carlson; K.G.V. Sigfridsson Clauss; I. Persson J. Phys.: Conf. Ser, 2016, 712, 012023.

[5] T. Kawaguchi; K. Fukuda; E. Matsubara J. Phys.: Condens. Matter, 2017, 29, 113002.