I21: an advanced high-resolution resonant inelastic X-ray scattering beamline at Diamond Light Source.

The I21 beamline at Diamond Light Source is dedicated to advanced resonant inelastic X-ray scattering (RIXS) for probing charge, orbital, spin and lattice excitations in materials across condensed matter physics, applied sciences and chemistry. Both the beamline and the RIXS spectrometer employ divergent variable-line-spacing gratings covering a broad energy range of 280-3000 eV. A combined energy resolution of ∼35 meV (16 meV) is readily achieved at 930 eV (530 eV) owing to the optimized optics and the mechanics. Considerable efforts have been paid to the design of the entire beamline, particularly the implementation of the collection mirrors, to maximize the X-ray photon throughput. The continuous rotation of the spectrometer over 150° under ultra high vacuum and a cryogenic manipulator with six degrees of freedom allow accurate mappings of low-energy excitations from solid state materials in momentum space. Most importantly, the facility features a unique combination of the high energy resolution and the high photon throughput vital for advanced RIXS applications. Together with its stability and user friendliness, I21 has become one of the most sought after RIXS beamlines in the world.

Stepwise observation and quantification and mixed matrix membrane separation of CO2 within a hydroxy-decorated porous host.

The identification of preferred binding domains within a host structure provides important insights into the function of materials. State-of-the-art reports mostly focus on crystallographic studies of empty and single component guest-loaded host structures to determine the location of guests. However, measurements of material properties (e.g., adsorption and breakthrough of substrates) are usually performed for a wide range of pressure (guest coverage) and/or using multi-component gas mixtures. Here we report the development of a multifunctional gas dosing system for use in X-ray powder diffraction studies on Beamline I11 at Diamond Light Source. This facility is fully automated and enables in situ crystallographic studies of host structures under (i) unlimited target gas loadings and (ii) loading of multi-component gas mixtures. A proof-of-concept study was conducted on a hydroxyl-decorated porous material MFM-300(VIII) under (i) five different CO2 pressures covering the isotherm range and (ii) the loading of equimolar mixtures of CO2/N2. The study has successfully captured the structural dynamics underpinning CO2 uptake as a function of surface coverage. Moreover, MFM-300(VIII) was incorporated in a mixed matrix membrane (MMM) with PIM-1 in order to evaluate the CO2/N2 separation potential of this material. Gas permeation measurements on the MMM show a great improvement over the bare PIM-1 polymer for CO2/N2 separation based on the ideal selectivity.

I12: the Joint Engineering, Environment and Processing (JEEP) beamline at Diamond Light Source.

I12 is the Joint Engineering, Environmental and Processing (JEEP) beamline, constructed during Phase II of the Diamond Light Source. I12 is located on a short (5 m) straight section of the Diamond storage ring and uses a 4.2 T superconducting wiggler to provide polychromatic and monochromatic X-rays in the energy range 50-150 keV. The beam energy enables good penetration through large or dense samples, combined with a large beam size (1 mrad horizontally × 0.3 mrad vertically). The beam characteristics permit the study of materials and processes inside environmental chambers without unacceptable attenuation of the beam and without the need to use sample sizes which are atypically small for the process under study. X-ray techniques available to users are radiography, tomography, energy-dispersive diffraction, monochromatic and white-beam two-dimensional diffraction/scattering and small-angle X-ray scattering. Since commencing operations in November 2009, I12 has established a broad user community in materials science and processing, chemical processing, biomedical engineering, civil engineering, environmental science, palaeontology and physics.

Fast X-ray powder diffraction on I11 at Diamond.

The commissioning and performance characterization of a position-sensitive detector designed for fast X-ray powder diffraction experiments on beamline I11 at Diamond Light Source are described. The detecting elements comprise 18 detector-readout modules of MYTHEN-II silicon strip technology tiled to provide 90° coverage in 2θ. The modules are located in a rigid housing custom designed at Diamond with control of the device fully integrated into the beamline data acquisition environment. The detector is mounted on the I11 three-circle powder diffractometer to provide an intrinsic resolution of Δ2θ approximately equal to 0.004°. The results of commissioning and performance measurements using reference samples (Si and AgI) are presented, along with new results from scientific experiments selected to demonstrate the suitability of this facility for powder diffraction experiments where conventional angle scanning is too slow to capture rapid structural changes. The real-time dehydrogenation of MgH(2), a potential hydrogen storage compound, is investigated along with ultrafast high-throughput measurements to determine the crystallite quality of different samples of the metastable carbonate phase vaterite (CaCO(3)) precipitated and stabilized in the presence of amino acid molecules in a biomimetic synthesis process.