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We describe an ultra‐compact setup for in situ X‐ray diffraction on the inelastic X‐ray scattering beamline ID20 at the European Synchrotron Radiation Facility. The main motivation for the design and construction of this setup is the increasing demand for on‐the‐fly sample characterization, as well as ease of navigation through a sample's phase diagram, for example subjected to high‐pressure and/or high‐temperature conditions. We provide technical details and demonstrate the performance of the setup. [ABSTRACT FROM AUTHOR]

Owing to the availability of bright X-rays sources such as the ESRF-EBS, inelastic X-ray scattering of samples contained in complex sample environments, including high pressure devices, has become feasible. Compared to well-established characterization techniques such as X-ray diffraction or X-ray absorption fine structure spectroscopy, inelastic X-ray scattering of samples under extreme conditions is a relatively novel probe. However, unique information about the electronic, magnetic, and local atomic structure is accessible with inelastic X-ray scattering. Here, capabilities of beamline ID20 of the ESRF in the field of high pressure inelastic X-ray scattering are presented and some recent activities are reviewed. [ABSTRACT FROM AUTHOR]

A von Hamos spectrometer has been implemented in the vacuum interaction chamber 1 of the High Energy Density instrument at the European X-ray Free-Electron Laser facility. This setup is dedicated, but not necessarily limited, to X-ray spectroscopy measurements of samples exposed to static compression using a diamond anvil cell. Si and Ge analyser crystals with different orientations are available for this setup, covering the hard X-ray energy regime with a sub-eV energy resolution. The setup was commissioned by measuring various emission spectra of free-standing metal foils and oxide samples in the energy range between 6 and 11 keV as well as low momentum-transfer inelastic X-ray scattering from a diamond sample. Its capabilities to study samples at extreme pressures and temperatures have been demonstrated by measuring the electronic spin-state changes of (Fe0.5Mg0.5)O, contained in a diamond anvil cell and pressurized to 100 GPa, via monitoring the Fe K-fluorescence with a set of four Si(531) analyser crystals at close to melting temperatures. The efficiency and signal-to-noise ratio of the spectrometer enables valence-to-core emission signals to be studied and single pulse X-ray emission from samples in a diamond anvil cell to be measured, opening new perspectives for spectroscopy in extreme conditions research. [ABSTRACT FROM AUTHOR]

The effects of varying LiPF6 salt concentration and the presence of lithium bis(oxalate)borate additive on the electronic structure of commonly used lithium‐ion battery electrolyte solvents (ethylene carbonate–dimethyl carbonate and propylene carbonate) have been investigated. X‐ray Raman scattering spectroscopy (a non‐resonant inelastic X‐ray scattering method) was utilized together with a closed‐circle flow cell. Carbon and oxygen K‐edges provide characteristic information on the electronic structure of the electrolyte solutions, which are sensitive to local chemistry. Higher Li+ ion concentration in the solvent manifests itself as a blue‐shift of both the π* feature in the carbon edge and the carbonyl π* feature in the oxygen edge. While these oxygen K‐edge results agree with previous soft X‐ray absorption studies on LiBF4 salt concentration in propylene carbonate, carbon K‐edge spectra reveal a shift in energy, which can be explained with differing ionic conductivities of the electrolyte solutions. [ABSTRACT FROM AUTHOR]

A classic example of solid-state topochemical reactions is the ultraviolet-light induced photodimerization of α-trans-cinnamic acid (CA). Here, we report the first observation of an X-ray-induced dimerization of CA and monitor it in situ using nonresonant inelastic X-ray scattering spectroscopy (NRIXS). The time-evolution of the carbon core-electron excitation spectra shows the effects of two X-ray induced reactions: dimerization on a short time-scale and disintegration on a long time-scale. We used spectrum simulations of CA and its dimerization product, α-truxillic acid (TA), to gain insight into the dimerization effects. From the time-resolved spectra, we extracted component spectra and time-dependent weights corresponding to CA and TA. The results suggest that the X-ray induced dimerization proceeds homogeneously in contrast to the dimerization induced by ultraviolet light. We also utilized the ability of NRIXS for direct tomography with chemical-bond contrast to image the spatial progress of the reactions in the sample crystal. Our work paves the way for other time-resolved studies on chemical reactions using inelastic X-ray scattering. [ABSTRACT FROM AUTHOR]

The experimental investigation of structural properties, phase relations, chemical equilibria andtransport properties of material of the Earth's core and lower mantle requires pressures andtemperatures which are statically achievable only by the combination of diamond-anvil cells(DACs) and laser-heating.While X-ray diffraction (XRD), nuclear forward scattering (NFS) and X-ray absorption techniquesrequire measurement in forward scattering geometry, X-ray emission spectroscopy (XES) andnuclear inelastic scattering (NIS) strongly benefit from measurement at or near 90° with respect tothe incident beam. XES is a powerful tool for determining local structure and electronic state. NISyields the phonon density of states and and sound velocity of materials.We present a portable and versatile IR laser heating system, which is optimized for X-rayspectroscopy applications like XES and NIS at 90° scattering angle. In several aspects, the setupresembles common stationary laser heating systems installed at extreme conditions beamlines: a)incidence of the primary beam through one of the diamonds, b) double-sided on-axis heating withgeoheat-objectives and a single laser source, and c) simultaneous double-sided spectrometrictemperature measurement.Besides its portability, advantages of the described laser heating system for spectroscopicapplications at X-ray energies between 6 and 15 keV are the attenuation-free incidence of theprimary beam at the DAC through a small hole in the upstream mirror, and the versatility for futurecombined measurements of XES/XRD and NIS/NFS.We demonstrate the construction of the laser heating system and show XES and NIS measurementsof iron compounds, carried out at beamline P01 at PetraIII, DESY. [ABSTRACT FROM AUTHOR]