SOLEIL Research Articles

Development of hard X-ray photoelectron spectroscopy in liquid cells using optimized microfabricated silicon nitride membranes.

We present first hard X-ray photoelectron spectroscopy (HAXPES) results of aqueous salt solutions and dispersions of gold nanoparticles in liquid cells equipped with specially designed microfabricated thin silicon nitride membranes, with thickness in the 15-25 nm range, mounted in a high-vacuum-compatible environment. The experiments have been performed at the HAXPES endstation of the GALAXIES beamline at the SOLEIL synchrotron radiation facility. The low-stress membranes are fabricated from 100 mm silicon wafers using standard lithography techniques. Platinum alignment marks are added to the chips hosting the membranes to facilitate the positioning of the X-ray beam on the membrane by detecting the corresponding photoemission lines. Two types of liquid cells have been used, a static one built on an Omicron-type sample holder with the liquid confined in the cell container, and a circulating liquid cell, in which the liquid can flow in order to mitigate the effects due to beam damage. We demonstrate that the membranes are mechanically robust and able to withstand 1 bar pressure difference between the liquid inside the cell and vacuum, and the intense synchrotron radiation beam during data acquisition. This opens up new opportunities for spectroscopic studies of liquids.

Spatial resolution studies using point spread function extraction in optically read out Micromegas and GEM detectors

Optically read out gaseous detectors are used in track reconstruction and imaging applications requiring high granularity images. Among resolution-determining factors, the amplification stage plays a crucial role and optimizations of detector geometry are pursued to maximize spatial resolution. To compare Micro Pattern Gaseous Detector (MPGD) technologies, focused low-energy X-ray beams at the SOLEIL synchrotron facility were used to record and extract point spread function widths with MICRO-Mesh Gaseous Structure (icromegas) and Gas Electron Multiplier (GEM) detectors. Point spread function width of ≈108µm for Micromegas and ≈127µm for GEM foils were extracted. The scanning of the beam with different intensities, energies and across the detector active region can be used to quantify resolution-limiting factors and improve imaging detectors using MPGD amplification stages.

First Ab Initio Line Lists for Triatomic Sulfur-Containing Molecules: S2O and S3.

We present in this paper the first room temperature rovibrational line lists for the main isotopologues of disulfur monoxide (S2O) and thiozone (S3) variationally computed from newly developed ab initio potential energy and dipole moment surfaces (PESs and DMSs). S2O and S3 are supposed to be potential candidates for astronomical detection, especially in the Venusian atmosphere where sulfur chemistry plays a major role. Contrary to other stable sulfur-containing species like SO2 or H2S, there is much less experimental data for the short-lived reactive S2O and S3 molecules. Indeed, the infrared spectra of S2O and S3 are quite complicated to analyze without consistent theoretical predictions because they contain both high J (∼100) and a lot of hot band transitions, even at T = 296 K. In this work, we have constructed PESs based on the single-reference coupled cluster approach [CCSD(T)] and including corrections due to the scalar relativistic effects, DBOC, and highly excited Slater determinants. The structure of the excited electronic states of S3 was also discussed. The nuclear-motion Eckart-Watson Hamiltonian expressed in terms of normal-mode irreducible tensor operators was used to compute the energy levels. For line intensity calculation, ab initio DMSs were computed at the CCSD(T)/aug-cc-pV5Z level of the theory. Rotation-vibration patterns in the fundamental bands of S2O and S3 have been simulated taking into account the recent Fourier-transform spectra of S2O recorded at the SOLEIL synchrotron. The present work aims at providing line intensities of S2O and S3 that are missing in the literature as well as new spectroscopic support for atmospheric applications.

An energy-modified quantum defect method for the analysis of Rydberg spectra: Application to 2-butyne.

The high resolution Rydberg absorption spectrum of 2-butyne C4H6 recorded previously at the SOLEIL synchrotron facility has been interpreted using multichannel quantum defect theory (MQDT). The calculations are based on the continuum scattering calculations of Xu et al., J. Chem. Phys. 136, 154303 (2012) and of Jacovella et al., J. Phys. Chem. A 119, 12339 (2015) pertaining to the dipole-allowed excited state symmetries in absorption from the ground state. In contrast to the traditional approach of calculating low-lying electronic states first and then attempting to extend the calculations to ever higher energy, here the analysis proceeds through the extension of these detailed calculations of the electronic continuum scattering down into the discrete region of the spectrum. The continuum reaction matrices and dipole transition moments are adapted to the discrete Rydberg region via the use of an energy-modified formulation of MQDT theory and associated energy dependences of the quantum defects. The analysis reproduces more than 40 Rydberg states from n ≈ 10 down to the 3d and 4s levels with an rms error of better than 20 cm-1. These belong to five Rydberg series with three different molecular symmetries. While the approach predicts many additional series, most of these are calculated and observed to carry only little oscillator strength. The analysis shows that the Rydberg spectrum is dominated by the excitation of an e″ symmetry electron of fδ and gπ type, in line with what previous studies of the above-threshold shape resonance of 2-butyne have shown. The present study is intended to serve as an example showing how first principles continuum calculations may be useful for the interpretation of highly bound discrete states in a range that poses problems for the standard abinitio techniques. The quantitative treatment of the dipole absorption cross sections is deferred to a future paper.

New quantum assignments and analysis of high-resolution H212CO spectra in the range 3700–4450 cm-1

Four spectra of formaldehyde in natural isotopic abundance in the 3700–5200 cm-1 region were recorded at low temperature 160–166 K at Synchrotron SOLEIL for various pressures. Line positions and intensities were retrieved by non-linear least-squares curve-fitting procedures in the range 3700–4450 cm-1 and analyzed using ab initio based effective Hamiltonian and line intensities computed using new ab initio dipole moment surface. A new measured line list contains positions and intensities for 6177 features. Refined parameters of effective Hamiltonian were fitted to all assigned line positions with the RMS deviations of 0.001 cm-1. Updated line lists include intensity values based on ab initio variational calculations which were subsequently empirically optimized. Comparison of our theoretical simulation with previously available data as well as with high-resolution and low-resolution experimental spectra are reported.

Disentangling the Ligand and Electronic Structure in KVPO4F1-XOx Positive Electrode Materials by Valence-to-Core X-Ray Emission Spectroscopy

Among all positive electrode materials for K-ion batteries (KIBs), KVPO4F offers a high theoretical capacity of 131 mAh·g-1 and an average working potential reaching above 4.3 V vs K+/K, resulting in a theoretical energy density of up to 520 Wh·kg-1. [1] The anionic substitution of fluorine by oxygen in KVPO4F1-xOx (x = 0, 0.25, 0.5, 0.75, 1) induces an increasing working potential by activating the V3+/4+ and V4+/5+ redox couples and replacing the VO4F2 “ionic” entity by {V=O}O5 unit with a highly “covalent” vanadyl-type bond. [2] The accurate prediction of the electrode potential as well as the understanding of the mechanisms involved upon cycling requires the determination of how the coordination environment of the transition metal ion influences the ionicity/covalency of the metal-ligand bonds and thus the electronic structure. Nevertheless, discriminating these ligands remains a challenge due to the limited sensitivity to light elements of common characterization techniques such as X-ray diffraction and extended X-ray absorption fine structure. Despite the valuable information from these techniques, fundamental concerns still need to be addressed which include: i) the implication of the covalent V=O vanadyl bond in the electronic structure; ii) the difference of Vcis and Vtrans, the two different sites for V, in the electronic configuration of the material; and finally, (iii) the impact of F/O ligands on the electrochemical mechanism upon battery cycling.To address this issue, we employed valence-to-core Kβ X-ray emission spectroscopy (VtC XES) combined with ab initio modelling and conducted a systematic investigation of KVPO4F1-xOx: two distinct regions were identified in the spectra, Kβ" and Kβ2,5, which are critical to probe the electronic structure close to the Fermi level and to discriminate different ligands coordinated with the vanadium atoms. [3] Our approach allows distinguishing in KVPO4F1-xOx the contributions of V-F, V-O, and V=O bonds, with intensities at the Kβ" region highly correlated to the F- and O2- anionic composition. Additionally, the evolution of the features at the Kβ2,5 region is highly associated to the presence of short V=O bonds, strongly influencing the electrode potential of the material.Overall, we present a detailed and reliable approach for understanding the occupied electronic states of the electrode material, proving valuable for a thorough comprehension of the structural and redox mechanisms involved in batteries.AcknowledgementThis work was supported by the DESTINY Marie Skłodowska-Curie Actions COFUND PhD Programme (Grant Agreement #945357) co-funded by the European Union's Horizon2020 research and innovation program and the Synchrotron SOLEIL. ANR is also acknowledged for funding the RS2E network through the STORE-EX Labex Project ANR-10-LABX-76-01, and the ANR TROPIC project ANR-CE05-0026. Alistore-ERI network is also acknowledged.

Towards the Direct Observation of the Local and Electronic Structure Evolution of Positive Electrode Materials by X-Ray Raman Scattering and X-Ray Emission Spectroscopy

The emergence of high brilliance synchrotron sources and the availability of more sophisticated infrastructure have opened doors to advanced material characterization, enabling a profound understanding of new processes and mechanisms in battery research. [1] More specifically, non-resonant Valence-to-Core X-ray emission spectroscopy (VtC-XES) and X-ray Raman scattering (XRS) stand out as complementary photon-in/photon-out X-ray spectroscopy techniques. The unique capability of these techniques lies in their access to soft X-ray edges using a hard X-ray beam, providing comprehensive information on both the electronic and local structure, due to their high sensitivity to local structure and coordination. [2,3] In this work, two different families of materials with different compositions and crystal structures are studied using XES and XRS.The first part focuses on the detailed study of oxygen substituted KVPO4F1-xOx (x = 0, 0.25, 0.5, 0.75, 1) using VtC-XES combined to ab initio theoretical calculations. The average working potential increases with increasing oxygen content by activating the V3+/4+ and V4+/5+ redox couples and replacing the VO4F2 “ionic” entity by {V=O}O5 unit with a highly “covalent” vanadyl-type bond. [4] VtC-XES allowed us to distinguish the contributions of V-F, V-O, and V=O bonds in the local environment, with spectral intensities highly correlated to the F- and O2- anionic composition. In addition, specific spectral evolutions are also associated to the presence of highly covalent V=O bonds, strongly influencing the electrode potential of the material.The second part examines a series of electrochemically obtained LiyNiO2 layered oxide materials (y = 0.02, 0.25, 0.33, 0.5, 0.67, 1.0). VtC-XES performed at the Ni Kβ emission line allows to study the local structure evolution around Ni, whereas XRS spectroscopy at both the O K-edge and Ni L2,3 L-edges gives an access to the interplay between Ni and O through the hybridized states of Ni 3d and O 2p. [5] This work provides a survey on both the cationic and anionic redox processes, and unveils the underlying phenomena related to the charge compensation processes occurring in this material.Overall, we present a comprehensive study of different polyanionic and layered oxide positive electrode materials using complementary X-ray spectroscopic techniques to probe both the local and electronic structures. We demonstrate that they allow to follow and understand evolution and changes in the local structure in materials of intricate crystal structures.AcknowledgementThis work was supported by the DESTINY Marie Skłodowska-Curie Actions COFUND PhD Programme (Grant Agreement #945357) co-funded by the European Union's Horizon2020 research and innovation program and the Synchrotron SOLEIL. ANR is also acknowledged for funding the RS2E network through the STORE-EX Labex Project ANR-10-LABX-76-01. Alistore-ERI network is also acknowledged.

Mechanisms of void nucleation on neat and Glass Syntactic PolyPropylene using in situ synchrotron radiation tomography

The mechanisms of void nucleation of a hollow glass syntactic foam during tensile loading were studied in depth. Flat-notched geometries, cut-out from neat and Glass Syntactic PolyPropylene (GSPP), were investigated by in situ microtomography. Notched specimens with two notch root radii, 4 mm and 0.15 mm named respectively N4 and N0.15, to set initial triaxial stress state in the minimum cross section, were observed. Tomographic data sets, with a resolution of 1.3μm, from stepwise tensile loading, at the SOLEIL synchrotron radiation facilities, were retrieved from the notched zone. In addition, they allowed gathering both the width and thickness evolution in the minimum cross section, and the notch opening displacement during the tests.In line with literature, neat PolyPropylene (PP) showed crazes concentration at the specimen core in N4 specimen, whereas, in N0.15 specimen, they were located at the notch root. In isolated Hollow Glass Microspheres (HGM), mechanisms of crazing and debonding were correspondingly highlighted in the PP matrix and at the poles of HGM. Finally, in GSPP, decohesion follows the same trend as in neat PP, i.e. at the specimen core and near the notch, respectively in N4 and in N0.15 geometry. Scenarios of void nucleation and propagation were outlined. The initiation of the brittle crack in the GSPP is mainly due to the matrix-HGM decohesion followed by the coalescence of near neighbouring caps.

High resolution far-infrared synchrotron spectroscopy of 2-furfural conformers: Fundamental and hot bands.

In the continuity of a previous jet-cooled rovibrational study of trans and cis conformers of 2-furfural in the mid-infrared region (700-1750cm-1) [Chawananon et al., Molecules 28 (10), 4165 (2023)], the present work investigates the far-infrared spectroscopy of 2-furfural using a long path absorption cell coupled to a high-resolution Fourier transform spectrometer and synchrotron radiation at the AILES beamline of the SOLEIL synchrotron. Guided by anharmonic calculations, vibrational energy levels and excited-state rotational constants are sufficiently predictive for a complete assignment of all fundamental and combination bands up to 700cm-1, as well as the rovibrational analysis of 4 (1) low-frequency modes of trans-(cis-)2-furfural. A global rovibrational simulation, including far-infrared rovibrational lines and microwave and millimeter-wave rotational lines assigned in a previous study [Motiyenko et al., J. Mol. Spectrosc., 244, 9 (2007)] provides a reliable set of ground- and excited-state rotational parameters involving ring torsion, bending, and ring puckering modes of 2-furfural. In a second step, a rovibrational analysis of several hot band sequences, mainly involving the lowest frequency ring CHO torsion mode, is carried out. Reliable values of some anharmonic coefficients are obtained experimentally and could serve as a benchmark for validating advanced anharmonic calculations related to these large amplitude motions of flexible molecules.

First X-ray spectral ptychography and resonant ptychographic computed tomography experiments at the SWING beamline from Synchrotron SOLEIL.

X-ray ptychography and ptychographic computed tomography have seen a rapid rise since the advent of fourth-generation synchrotrons with a high degree of coherent radiation. In addition to quantitative multiscale structural analysis, ptychography with spectral capabilities has been developed, allowing for spatial-localized multiscale structural and spectral information of samples. The SWING beamline of Synchrotron SOLEIL has recently developed a nanoprobe setup where the endstation's first spectral and resonant ptychographic measurements have been successfully conducted. A metallic nickel wire sample was measured using 2D spectral ptychography in XANES mode and resonant ptychographic tomography. From the 2D spectral ptychography measurements, the spectra of the components of the sample's complex-valued refractive index, δ and β, were extracted, integrated along the sample thickness. By performing resonance ptychographic tomography at two photon energies, 3D maps of the refractive index decrement, δ, were obtained at the Ni K-edge energy and another energy above the edge. These maps allowed the detection of impurities in the Ni wire. The significance of accounting for the atomic scattering factor is demonstrated in the calculation of electron density near a resonance through the use of the δvalues. These results indicate that at the SWING beamline it is possible to conduct state-of-the-art spectral and resonant ptychography experiments using the nanoprobe setup.

Development of an x-ray polarimeter at the SOLEIL synchrotron.

Synchrotron radiation facilities provide highly polarized x-ray beams across a wide energy range. However, the exact type and degree of polarization vary according to the beamline and experimental setup. To accurately determine the angle and degree of linear polarization, a portable x-ray polarimeter has been developed. This setup consists of a silicon drift detector that rotates around a target made of high-density polyethylene. The imprint generated in the angular distribution of scattered photons from the target at a 90-degree angle between the incident x-rays and detector has been exploited to determine the beam polarization. Measurements were conducted at the GALAXIES beamline of the SOLEIL synchrotron. The expected angular distribution of the scattered photons for a given beam polarization was obtained through simulations using the Geant4 simulation toolkit. An excellent agreement between simulations and the collected data has been obtained, validating the setup and enabling a precise determination of the beam polarization.

Improving the characterization of red coloring matter from prehistoric cave art by means of laboratory confocal XRF depth profiling combined with synchrotron XRF imaging

Chemical in situ study of red coloring matter in cave art is challenging because characteristic trace elements can be present both in the matter and in the wall support, and the latter has a quite heterogeneous composition.In this study, a stalactite presenting red iron oxide coloring matter from La Garma cave, Northern Spain, has been analyzed with complementary techniques. The aims are, on the one hand, confirming for the first time the feasibility of confocal XRF (CXRF) depth-resolved scans to successfully separate the complex stratigraphy of red prehistoric coloring matter on a calcitic support. On the other hand, finding differentiation criteria and improving the characterization of this red iron-based coloring matter would help understand and virtually separate it from its support, as well as improve future in situ analyses in cave sites.CXRF depth-resolved scans were performed using the LouX3D device available in our laboratory. With this technique, we can precisely determine the chemical depth composition of an object, layer by layer, with a spatial resolution in the micrometer scale. These measurements were combined with a synchrotron induced micro-X-ray fluorescence (SR-µXRF) chemical mapping performed at the PUMA beamline, SOLEIL synchrotron. These highly sensitive measurements not available with any other non-destructive lab-based technique allow seeing a greater number of trace and minor elements associated with Fe. Complementing them with the direct depth-resolved information given by CXRF, it was possible to find differentiation criteria distinguishing the wall support and the coloring matter, finely characterize this red iron-based matter, and confirm the feasibility as well as the advantages of applying CXRF for the non-invasive technical study of prehistoric cave figures.

The far infrared absorption spectrum of D216O, D217O, and D218O: Experimental line positions, empirical energy levels and recommended line lists

The far infrared absorption spectra of D216O, D217O, and D218O are analyzed with improved accuracy and sensitivity in the 50–720 cm−1 range corresponding to the rotational band. Four room-temperature absorption spectra of highly deuterated water vapor were recorded at the SOLEIL synchrotron by high-resolution Fourier transform spectroscopy. Line centers are reported with a typical accuracy of 5 × 10−5 cm−1 for well isolated lines. The combined line list of about 9700 water lines was assigned to about 10 400 transitions of the nine stable water isotopologues (H2XO, HDXO, D2XO, with X = 16, 17, and 18). A total of 2885 transitions of eight bands involving the first five vibrational states were assigned to D216O. Among them, 2057 are newly reported. The obtained set of transition frequencies was merged with literature data to generate a new set of empirical energy levels for the first five vibrational states of D216O. A total of 1089 transitions of the (000)–(000) and (010)–(010) bands were measured for D217O. They were merged with literature sources to derive 724 empirical term values of seven vibrational states, up to 8088 cm−1. 348 D217O levels are newly determined. A set of 1150 transitions belonging to the (000)–(000) and (010)–(010) bands was measured for D218O. 3451 empirical energies of rotation–vibration levels up to 9222 cm−1 were retrieved using our observations and literature sources. The extension and accuracy of the derived empirical energy levels allow us to recommend new line lists with empirically corrected line positions for D216O, D217O, and D218O.

Analysis of New Measurements of 18O-substituted Isotopic Species 16O16O18O and 16O18O16O of Ozone in the THz and Far-Infrared Ranges

High-resolution spectra corresponding to the rotational and the ν2–ν2 bands of the two most abundant isotopic species of ozone with one heavy 18O oxygen atom were recorded using SOLEIL synchrotron radiation source in the range 30–200 cm−1. Additionally, the ν2 vibrational-rotational bands were recorded between 550 and 880 cm−1 using a classical glowbar source that made it possible to extend and refine information compared to published data on the observed transitions of these bands. The analyses of recorded spectra permitted us to deduce experimental set of energy levels for the ground (000) and the first bending (010) vibrational states, which significantly exceeds literature data in terms of rotational quantum numbers. For both isotopic species, the weighted fits of all experimental line positions were carried out including previously published microwave data. As a result of this work, the improved values of rotational and centrifugal distortion parameters for the states (000) and (010) were obtained that permitted modelling the experimental line positions with a weighted standard deviation of 1.284 (2235 transitions) and 0.908 (4597 transitions), respectively, for 16O16O18O, and 1.168 (824 transitions) and 1.724 (2381 transitions) for 16O18O16O.

Experimental characterization of SiCH+via single-photon ionization of gas-phase SiCH.

SiCH and its cation have consistently emerged as predicted species in models of silicon chemistry within the interstellar medium, although they remain unobserved in space. Hindered by their intrinsic instability, no spectroscopic insights have been gleaned concerning the SiCH+ cation. In this study, we present experimental measurements on the SiCH+ cation through single-photon ionization spectroscopy of the SiCH radical within the 8.0-11.0eV range. Gas-phase SiCH radicals were generated through chemical reactions involving CHx (x = 0-3) and SiHy (y = 0-3) within a microwave discharge flow-tube reactor. Employing a double imaging photoelectron/photoion coincidence spectrometer on the DESIRS beamline at the SOLEIL synchrotron, we recorded mass-selected ion yield and photoelectron spectra. From the analysis of the photoelectron spectrum supported by abinitio calculations and Franck-Condon simulations, the adiabatic ionization energies for the transitions from the X2Π ground electronic state of SiCH toward the X+3Σ- and A+3Π electronic states of SiCH+ have been derived [8.935(6) and 10.664(6) eV, respectively, without spin-orbit correction]. The contribution from the less stable isomer HSiC has been explored in our analysis and ruled out in our experiments.

Advanced spectroscopic investigation of colour centres in LiF crystals irradiated with monochromatic hard x-rays

Nominally-pure lithium fluoride (LiF) crystals were irradiated with monochromatic hard x-rays of energy 5, 7, 9 and 12 keV at the METROLOGIE beamline of the SOLEIL synchrotron facility, in order to understand the role of the selected x-ray energy on their visible photoluminescence (PL) response, which is used for high spatial resolution 2D x-ray imaging detectors characterized by a wide dynamic range. At the energies of 7 and 12 keV the irradiations were performed at five different doses corresponding to five uniformly irradiated areas, while at 5 and 9 keV only two irradiations at two different doses were carried out. The doses were planned in a range between 4 and 1.4 × 103 Gy (10.5 mJ cm−3 to 3.7 J cm−3), depending on the x-ray energy. After irradiation at the energies of 7 and 12 keV, the spectrally-integrated visible PL intensity of the F2 and F3 + colour centres (CCs) generated in the LiF crystals, carefully measured by fluorescence microscopy under blue excitation, exhibits a linear dependence on the irradiation dose in the investigated dose range. This linear behaviour was confirmed by the optical absorption spectra of the irradiated spots, which shows a similar linear behaviour for both the F2 and F3 + CCs, as derived from their overlapping absorption band at around 450 nm. At the highest x-ray energy, the average concentrations of the radiation-induced F, F2 and F3 + CCs were also estimated. The volume distributions of F2 defects in the crystals irradiated with 5 and 9 keV x-rays were reconstructed in 3D by measuring their PL signal using a confocal laser scanning microscope operating in fluorescence mode. On-going investigations are focusing on the results obtained through this z-scanning technique to explore the potential impact of absorption effects at the excitation laser wavelength.

Valence shell electronically excited states of norbornadiene and quadricyclane.

The absolute photoabsorption cross sections of norbornadiene (NBD) and quadricyclane (QC), two isomers with chemical formula C7H8 that are attracting much interest for solar energy storage applications, have been measured from threshold up to 10.8eV using the Fourier transform spectrometer at the SOLEIL synchrotron radiation facility. The absorption spectrum of NBD exhibits some sharp structure associated with transitions into Rydberg states, superimposed on several broad bands attributable to valence excitations. Sharp structure, although less pronounced, also appears in the absorption spectrum of QC. Assignments have been proposed for some of the absorption bands using calculated vertical transition energies and oscillator strengths for the electronically excited states of NBD and QC. Natural transition orbitals indicate that some of the electronically excited states in NBD have a mixed Rydberg/valence character, whereas the first ten excited singlet states in QC are all predominantly Rydberg in the vertical region. In NBD, a comparison between the vibrational structure observed in the experimental 11B1-11A1 (3sa1 ← 5b1) band and that predicted by Franck-Condon and Herzberg-Teller modeling has necessitated a revision of the band origin and of the vibrational assignments proposed previously. Similar comparisons have encouraged a revision of the adiabatic first ionization energy of NBD. Simulations of the vibrational structure due to excitation from the 5b2 orbital in QC into 3p and 3d Rydberg states have allowed tentative assignments to be proposed for the complex structure observed in the absorption bands between ∼5.4 and 7.0eV.

ProSPyX: software for post-processing images of X-ray ptychography with spectral capabilities.

X-ray ptychography is a coherent diffraction imaging technique based on acquiring multiple diffraction patterns obtained through the illumination of the sample at different partially overlapping probe positions. The diffraction patterns collected are used to retrieve the complex transmittivity function of the sample and the probe using a phase retrieval algorithm. Absorption or phase contrast images of the sample as well as the real and imaginary parts of the probe function can be obtained. Furthermore, X-ray ptychography can also provide spectral information of the sample from absorption or phase shift images by capturing multiple ptychographic projections at varying energies around the resonant energy of the element of interest. However, post-processing of the images is required to extract the spectra. To facilitate this, ProSPyX, a Python package that offers the analysis tools and a graphical user interface required to process spectral ptychography datasets, is presented. Using the PyQt5 Python open-source module for development and design, the software facilitates extraction of absorption and phase spectral information from spectral ptychographic datasets. It also saves the spectra in file formats compatible with other X-ray absorption spectroscopy data analysis software tools, streamlining integration into existing spectroscopic data analysis pipelines. To illustrate its capabilities, ProSPyX was applied to process the spectral ptychography dataset recently acquired on a nickel wire at the SWING beamline of the SOLEIL synchrotron.

Using synchrotron high-resolution powder X-ray diffraction for the structure determination of a new cocrystal formed by two active principle ingredients.

The crystal structure of a new 1:1 cocrystal of carbamazepine and S-naproxen (C15H12N2O·C14H14O3) was solved from powder X-ray diffraction (PXRD). The PXRD pattern was measured at the high-resolution beamline CRISTAL at synchrotron SOLEIL (France). The structure was solved using Monte Carlo simulated annealing, then refined with Rietveld refinement. The positions of the H atoms were obtained from density functional theory (DFT) ground-state calculations. The symmetry is orthorhombic with the space group P212121 (No. 19) and the following lattice parameters: a = 33.5486 (9), b = 26.4223 (6), c = 5.3651 (10) Å and V = 4755.83 (19) Å3.

State-of-the-art multimodal scanning hard X-ray imaging and tomography sheds light at multiple length-scales on biomineralization related processes

Biomineralization is a widespread process among living organisms, playing a significant role in the formation and preservation of geological structures, biogeochemical cycles, regulation of ocean chemistry, and carbon sequestration. Moreover pathological biomineralization has a huge impact on human health. The growth of biominerals provides a rich area for research at multiple length-scales since they have controlled hierarchical structures from nano-to macroscopic scales. Here, we provide an overview on the potentials of the state-of-the-art scanning hard X-ray imaging and tomography methods developed at the NANOSCOPIUM beamline at Synchrotron Soleil in such studies. Multimodal scanning imaging provides simultaneous information on the elemental composition by X-ray fluorescence (XRF) spectrometry, on the sample morphology by absorption contrast imaging, on the crystalline structure by X-ray diffraction, and on the luminescence characteristics by X-ray Excited Optical Luminescence. As illustrated through diverse research cases about biomineralization in stromatolites and pathological calcification, such a versatile portfolio of X-ray imaging techniques provides unique complementary information to conventional laboratory techniques on biominerals and the underlying mineral precipitation processes.