Spectroscopy Beamline Research Articles

The Inner Shell Spectroscopy beamline at NSLS-II: a facility for in situ and operando X-ray absorption spectroscopy for materials research.

The Inner Shell Spectroscopy (ISS) beamline on the 8-ID station at the National Synchrotron Light Source II (NSLS-II), Upton, NY, USA, is a high-throughput X-ray absorption spectroscopy beamline designed for in situ, operando, and time-resolved material characterization using high monochromatic flux and scanning speed. This contribution discusses the technical specifications of the beamline in terms of optics, heat load management, monochromator motion control, and data acquisition and processing. Results of the beamline tests demonstrating the quality of the data obtainable on the instrument, possible energy scanning speeds, as well as long-term beamline stability are shown. The ability to directly control the monochromator trajectory to define the acquisition time for each spectral region is highlighted. Examples of studies performed on the beamline are presented. The paper is concluded with a brief outlook for future developments.

Emergence of the first XAFS/XRF beamline in the Middle East: providing studies of elements and their atomic/electronic structure in pluridisciplinary research fields.

XAFS/XRF is a general-purpose absorption spectroscopy beamline at the Synchrotron-light for Experimental Science and Applications in the Middle East (SESAME), Jordan. Herein, its optical layout is presented along with its powerful capabilities in collecting absorption and fluorescence spectra within a wide energy range (4.7-30 keV). The beamline is equipped with a conventional fixed-exit double-crystal monochromator that allows the collection of an X-ray absorption spectrum within a few minutes in step-by-step mode. An on-the-fly scanning mode will be implemented shortly where the acquisition time will be reduced to less than a minute per scan. The full automation of the beamline allows performing successive measurements under different conditions. The different experimental setups and special features available to users are reported. Examples of XRF and XAFS measurements are presented, showing the performance of the beamline under different standard conditions.

Optical Layout and Endstation Concept for the Enhanced Liquid Interface Spectroscopy and Analysis (ELISA) Beamline at BESSY-II

Optical Layout and Endstation Concept for the Enhanced Liquid Interface Spectroscopy and Analysis (ELISA) Beamline at BESSY-II

Beamline commissioning for microscopic measurements with ultraviolet and soft X-ray beam at the upgraded beamline BL-13B of the Photon Factory.

Beamline 13 of the Photon Factory has been in operation since 2010 as a vacuum ultraviolet and soft X-ray undulator beamline for X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and angle-resolved photoelectron spectroscopy (ARPES) experiments. The beamline and the end-station at branch B have been recently upgraded, enabling microscopic XPS, XAS, and ARPES measurements to be performed. In 2015, a planar undulator insertion device was replaced with an APPLE-II (advanced planar polarized light emitter II) undulator. This replacement allows use of linear, circular, and elliptical polarized light between 48 and 2000 eV with photon intensities of 109-1013 photons s-1. For microscopic measurements, a toroidal post-mirror was renewed to have more focused beam with profile sizes of 78 µm (horizontal) × 15 µm (vertical) and 84 µm × 11 µm at photon energies of 100 and 400 eV, respectively. A high-precision sample manipulator composed of an XYZ translator, a rotary feedthrough, and a newly developed goniometer, which is essential for microscopic measurements, has been used to control a sample specimen in six degrees of freedom, i.e. translation in the X, Y, and Z directions and rotation in the polar, azimuthal, and tilt directions. To demonstrate the performance of the focused beams, one- and two-dimensional XPS and XAS scan measurements of a copper grid have been performed. It was indicated from analysis of XPS and XAS intensity maps that the actual spatial resolution can be determined by the beam size.

Towards a dynamic compression facility at the ESRF.

Results of the 2018 commissioning and experimental campaigns of the new High Power Laser Facility on the Energy-dispersive X-ray Absorption Spectroscopy (ED-XAS) beamline ID24 at the ESRF are presented. The front-end of the future laser, delivering 15 J in 10 ns, was interfaced to the beamline. Laser-driven dynamic compression experiments were performed on iron oxides, iron alloys and bismuth probed by online time-resolved XAS.

Reusing Face Covering Masks: Probing the Impact of Heat Treatment.

The COVID-19 pandemic resulted in imminent shortages of personal protective equipment such as face masks. To address the shortage, new sterilization or decontamination procedures for masks are quickly being developed and employed. Dry heat and steam sterilization processes are easily scalable and allow treatment of large sample sizes, thus potentially presenting fast and efficient decontamination routes, which could significantly ease the rapidly increasing need for protective masks globally during a pandemic like COVID-19. In this study, a suite of structural and chemical characterization techniques, including scanning electron microscopy (SEM), contact angle, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman were utilized to probe the heat treatment impact on commercially available 3M 8210 N95 Particulate Respirator and VWR Advanced Protection surgical mask. Unique to this study is the use of the synchrotron-based In situ and Operando Soft X-ray Spectroscopy (IOS) beamline (23-ID-2) housed at the National Synchrotron Light Source II at Brookhaven National Laboratory for near-edge X-ray absorption spectroscopy (NEXAFS).

Reducing the thermal deformation of InSb crystal by using double-bounce HHRMs in the TPS tender X-ray absorption spectroscopy beamline.

The Taiwan Photon Source (TPS) with high brightness and energy tunability is suitable for applications in spectroscopy. The tender X-ray absorption beamline will be optimized for X-ray absorption spectroscopy measurements using a bending-magnet source in a unique photon energy range (1.7-10 keV) and two crystal pairs [InSb(111) and Si(111)] separated using back-to-back double-crystal monochromators (DCMs). InSb crystals are typically used in the lower photon energy range of 1.7-3.5 keV. However, the poor thermal conductivity of InSb crystals leads to severe deformation. This factor should be considered when the monochromator is installed on a tender X-ray beamline in a storage ring with a high power density. There are many approaches to reducing the thermal load on the first crystal of a DCM. Double-bounce high harmonics rejection mirrors in front of the DCM serve not only to reduce the high-order harmonics but also to absorb considerable quantities of heat. Two coating stripes on the silicon surfaces with a variable incident angle will be key to solving the thermal load on this beamline.

On-axis sample viewer with flexible working distance for an X-ray spectroscopy beamline.

Conducting research using micrometer-sized X-ray beams with small samples is common at modern synchrotron X-ray sources. Often, the relative alignment between the X-ray beam and sample is time consuming. An on-axis or coaxial camera system with a view of the sample in a direction along the path of the X-ray beam with its depth of field set to coincide with the location of the focal spot of the X-ray beam is preferred. Besides the use of a drilled mirror, I propose the use of a Pellicle mirror to create an on-axis viewer that allows various sample environments and X-ray beam sizes.

In Situ Synchrotron X‐Ray Absorption Spectroscopy Studies of Anode Materials for Rechargeable Batteries

AbstractTaking advantage of a high‐flux light source, synchrotron X‐ray absorption spectroscopy (XAS) beamline is able to perform in situ/ex situ, element‐selective, and qualitative/quantitative experiments to elucidate electrochemical reaction mechanisms of batteries accurately and efficiently. In situ synchrotron XAS probes dynamic electronic and local atomic structure information, including valence state, charge transfer, local geometry and symmetry, bond number/length/type and disorder degree, of target elements of significance during battery operation, which facilitates to promote the development of rechargeable batteries by building accurate structure‐performance relationships fundamentally. In this review, the basic principles for XAS are briefly introduced, design strategies for in situ XAS experiments are proposed, salient in situ XAS studies of battery anodes are summarized, and current challenges and future opportunities based on XAS measurements are also outlined.

X-SPEC: a 70 eV to 15 keV undulator beamline for X-ray and electron spectroscopies.

X-SPEC is a high-flux spectroscopy beamline at the KIT (Karlsruhe Institute of Technology) Synchrotron for electron and X-ray spectroscopy featuring a wide photon energy range. The beamline is equipped with a permanent magnet undulator with two magnetic structures of different period lengths, a focusing variable-line-space plane-grating monochromator, a double-crystal monochromator and three Kirkpatrick-Baez mirror pairs. By selectively moving these elements in or out of the beam, X-SPEC is capable of covering an energy range from 70 eV up to 15 keV. The flux of the beamline is maximized by optimizing the magnetic design of the undulator, minimizing the number of optical elements and optimizing their parameters. The beam can be focused into two experimental stations while maintaining the same spot position throughout the entire energy range. The first experimental station is optimized for measuring solid samples under ultra-high-vacuum conditions, while the second experimental station allows in situ and operando studies under ambient conditions. Measurement techniques include X-ray absorption spectroscopy (XAS), extended X-ray absorption fine structure (EXAFS), photoelectron spectroscopy (PES) and hard X-ray PES (HAXPES), as well as X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS).

A new SOLARIS beamline optimized for X-ray spectroscopy in the tender energy range

A new X-ray absorption spectroscopy (XAS) beamline is currently under construction at a bending magnet of the National Synchrotron Radiation Centre SOLARIS. The front end of this beamline was installed in April 2020. This beamline has a few outstanding characteristic features: The monochromator is a fixed exit beam Lemmonier type monochromator allowing to cover the pursued energy range (1 keV to ~15 keV) with 3 sets of crystals: KAP (100) + multilayer, InSb (111) and Ge (220). The monochromator is a high vacuum system allowing the change of crystals in less than an hour. In order to minimize absorption of photons no windows will be installed in the beamline down to the monochromator, and just one thin polypropylene window will be used for separating the vacuum of the monochromator from the ionization chambers and the sample chamber. A special differential ion pump will be installed to maintain the pressure difference of four orders of magnitude between the storage ring and the monochromator. As SOLARIS is a low energy machine, the beamline can be built without any radiation safety hutches without exceeding the strict low radiation safety levels. The straightforward design of the beamline without additional optical elements, its compact overall dimensions and an easy to handle monochromator make this beamline especially user friendly. In combination with the characteristics of the 1.5 GeV SOLARIS storage ring this beamline will be specifically attractive for the tender X-ray range, i.e. the K-edges of important elements such as P, S, Si, Al and Mg.

Motor-driven autonomous system for controlling beamline iris diaphragm apertures

At the collinear apparatus for laser spectroscopy and applied sciences (COALA) at TU Darmstadt, collinear laser spectroscopy is applied to perform high-precision measurements of atomic transition frequencies and high voltages in an ultra-high vacuum beamline. In such laser spectroscopy beamlines, iris diaphragms are used to reduce ion beam divergence, and to ensure a good laser and ion beam overlap. Since the system that controls the diameter of the apertures presents strong hysteresis, an automated adjustment is desirable to enhance reproducibility in the aperture settings, and to reduce the effort in performing measurements where different diameters are required, especially in alternating collinear and anti-collinear measurements. To achieve this, the Iris Mover system was designed and implemented. The Iris Mover system consists of motor-driven iris apertures which can be easily controlled by users through a computer, and which accounts for hysteresis effects. Here, we explain the design process of the Iris Mover and demonstrate and discuss its functionality.

Clamp cells for high pressure neutron scattering at low temperatures and high magnetic fields at Heinz Maier-Leibnitz Zentrum (MLZ)

ABSTRACT We report on the feasibility of high pressure neutron scattering in clamp cells at various diffraction and spectroscopy beamlines in the Heinz Maier-Leibnitz Zentrum in Garching (Germany). The cells are compact in order to fit into the existing sample environment devices and to accommodate samples up to about 150 mm³ at pressures above 1 GPa.

The Macquarie Deformation-DIA facility at the Australian Synchrotron: A tool for high-pressure, high-temperature experiments with synchrotron radiation.

The Macquarie University Deformation-DIA (MQ D-DIA) multi-anvil apparatus at the Australian Synchrotron provides a new experimental facility that enables simultaneous high-pressure and high-temperature in situ synchrotron experimentation in Australia. The MQ D-DIA can be easily deployed at any of a number of beamlines at the Australian Synchrotron, and we describe its installation at the x-ray absorption spectroscopy beamline, which enables in situ x-ray absorption near-edge spectroscopy and energy-scanning x-ray diffraction. A simple, reliable, and x-ray transparent high-pressure cell assembly has been developed for the D-DIA for which load/pressure and heater power/temperature relationships have been calibrated using in situ x-ray diffraction and "offline" mineral equilibration experiments. Additionally, we have mapped temperature distribution within the assembly using a new quantitative electron microprobe mapping technique developed for fine-grained polyphase samples. We are now investigating the speciation of geologically important trace elements in silicate melts (e.g., Zr, U, and Th) measured in situ under high pressure and temperature conditions corresponding to the Earth's mantle. Pressure-dependent changes in speciation influence partitioning behavior, and therefore the distribution in the Earth, of many trace elements. However, previous ex situ investigations are hampered by uncertainty as to whether high-pressure speciation can be faithfully recorded in samples recovered to ambient conditions. We present preliminary results showing an increase in the coordination number of Zr dissolved as a trace component of a sodium-rich silicate melt with pressure. These results also indicate that silicate melt composition exerts a strong influence on Zr speciation.

Development of UHV pulsed laser deposition set-up for in-situ photoelectron spectroscopic study at ARPES beamline, Indus-1 synchrotron radiation source, India

We have developed an Ultra-High Vacuum (UHV) compatible Pulsed Laser Deposition (PLD) set-up at Angle Resolved Photo Electron Spectroscopy (ARPES) beamline (BL-3) at Indus-1 synchrotron radiation source, Raja Ramanna Centre for Advanced Technology, Indore, India. The set-up is successfully tested and integrated at beamline for in-situ photoelectron spectroscopic (PES) studies of thin films. In present PLD set-up, quick in-situ transfer of deposited thin films to analysis chamber enables the surface sensitive PES measurements on atomically cleaned surfaces without the requirement of any sputtering. This set-up has the capability of thin film depositions using six number of one-inch targets with precise control of various deposition parameters at a base pressure of ∼1x10−9 mbar. To explore the capability of the system, a set of thin films of HfO2, 5 % Ga2O3 doped ZnO (GZO) and GZO/HfO2 are deposited and the band offset of GZO/HfO2 heterostructure is investigated by in-situ PES measurements using synchrotron radiation. The film surface is found to be contamination free, which demonstrates the capability of the set-up for in-situ PES studies. The Hf 4f and Zn 3d core level peaks along with valence band maxima positions are used to determine the valence band offset. The valence band offset is found to be 0.31 ± 0.08 eV, which is the first result reported on this heterostructure system.

The application of confocal depth-resolved micro-X-ray absorption spectroscopy to study colorant copper in ancient lead-silica glassy system at the Beijing Synchrotron Radiation Facility

A new mobilizable confocal fluorescence end-station for depth-resolved micro-X-ray absorption spectroscopy being setup with optimal settings and applied to copper in lead-based glaze and pigment of ancient Chinese ceramics. The major equipment of the confocal micro-spots system included two polycapillary half-lens: one is defines the incident beam path and another polycapillary half-lens at 90°defines the probe sample volume, and operate with an efficient automatic alignment program by evolutionary algorithm. This depth-resolved system was examined on a general X-ray absorption spectroscopy (XAS) beamline at the Beijing Synchrotron Radiation Facility (BSRF, 1W1A/1W2B). The application in this case report that the status of copper in various lead-silica amorphous materials and speciation in different depth of lead-rich glassy layer from aged China. The results shown that this equipment working well and can obtaining equal data from surface to certain depth of copper colorant. Also, although the large number of lead component existing in the various glassy matrix but due to high-intensity of synchrotron radiation light and optimize-designed structure of facility, the results still revealing the preeminent ability of spatially resolution as well. As a mobilizable end-station with advantage, such as non-destructive and adjustable micro-spots, this confocal system in BSRF can improve the function and flexibility of general XAS beamlines, and indicating their capabilities to applicating to archaeological and cultural heritage field more deeply and widely in further.

EXAFS Study on the Coordination Chemistry of the Solvated Copper(II) Ion in a Series of Oxygen Donor Solvents.

The structures of the solvated copper(II) ion in water and nine organic oxygen donor solvents with similar electron-pair donor ability, but with different space-demanding properties at coordination, have been studied by EXAFS. N,N′-Dimethylpropyleneurea and N,N,N′,N′-tetramethylurea are sufficiently space demanding at coordination to make the axial positions not accessible, resulting in square-planar copper(II) solvate complexes with an intense green color. The mean Cu–O bond distances in these two solvate complexes are 1.939(3) and 1.935(3) Å, respectively. The best fits of the remaining solvates, which are light blue in different hues, are obtained with a Jahn–Teller distorted-octahedral model consisting of four strongly bound solvent molecules in the equatorial positions at 1.96(2) Å and two in the axial positions but with different Cu–Oax bond distances: ca. 2.15 and 2.32 Å. This is in agreement with observations in solid-state structures of compounds containing hexaaquacopper(II) complexes crystallizing in noncentrosymmetric space groups and all reported crystal structures containing a [Cu(H2O)5(O-ligand)] complex with Jahn–Teller distortion. Such a structure is in agreement with previous EPR and EXAFS studies proving the hydrated copper(II) ion to be a noncentrosymmetric complex in aqueous solution. The refinements of the EXAFS data of the solids [Cu(H2O)6](ClO4)2, [Cu(H2O)6](BrO3)2, [Cu(H2O)6]SiF6, Cu(NO3)2·2.5H2O, and CuSO4·5H2O gave Cu–O bond distances significantly different from those reported in the crystallographic studies but similar to the configuration and bond distances in the hydrated copper(II) ion in aqueous solution. This may depend on whether the orientation of the axial positions is random in one or three dimensions, giving a mean structure of the solid with symmetry higher than that of the individual complexes. This study presents the very first experimental data from the new X-ray absorption spectroscopy beamline Balder at the MAX IV synchrotron radiation facility in Lund, Sweden, as well as the utilized properties of the beamline.

Revealing the single electron pocket of FeSe in a single orthorhombic domain

We measure the electronic structure of FeSe from within individual orthorhombic domains. Enabled by an angle-resolved photoemission spectroscopy beamline with a highly focused beamspot (nano-ARPES), we identify clear stripe-like orthorhombic domains in FeSe with a length scale of approximately 1-5~$\mu$m. Our photoemission measurements of the Fermi surface and band structure within individual domains reveal a single electron pocket at the Brillouin zone corner. This result provides clear evidence for a one-electron pocket electronic structure of FeSe, observed without the application of uniaxial strain, and calls for further theoretical insight into this unusual Fermi surface topology. Our results also showcase the potential of nano-ARPES for the study of correlated materials with local domain structures.

Novel beamline for attosecond transient reflection spectroscopy in a sequential two-foci geometry.

We present an innovative beamline for extreme ultraviolet (XUV)-infrared (IR) pump-probe reflection spectroscopy in solids with attosecond temporal resolution. The setup uses an actively stabilized interferometer, where attosecond pulse trains or isolated attosecond pulses are produced by high-order harmonic generation in gases. After collinear recombination, the attosecond XUV pulses and the femtosecond IR pulses are focused twice in sequence by toroidal mirrors, giving two spatially separated interaction regions. In the first region, the combination of a gas target with a time-of-flight spectrometer allows for attosecond photoelectron spectroscopy experiments. In the second focal region, an XUV reflectometer is used for attosecond transient reflection spectroscopy (ATRS) experiments. Since the two measurements can be performed simultaneously, precise pump-probe delay calibration can be achieved, thus opening the possibility for a new class of attosecond experiments on solids. Successful operation of the beamline is demonstrated by the generation and characterization of isolated attosecond pulses, the measurement of the absolute reflectivity of SiO2, and by performing simultaneous photoemission/ATRS in Ge.

Efficient table-top dual-wavelength beamline for ultrafast transient absorption spectroscopy in the soft X-ray region

We present a table-top beamline providing a soft X-ray supercontinuum extending up to 370 eV from high-order harmonic generation with sub-13 fs 1300 nm driving pulses and simultaneous production of sub-5 fs pulses centered at 800 nm. Optimization of high harmonic generation in a long and dense gas medium yields a photon flux of ~ 1.4 × 106 photons/s/1% bandwidth at 300 eV. The temporal resolution of X-ray transient absorption experiments with this beamline is measured to be 11 fs for 800 nm excitation. This dual-wavelength approach, combined with high flux and high spectral and temporal resolution soft X-ray absorption spectroscopy, is a new route to the study of ultrafast electronic dynamics in carbon-containing molecules and materials at the carbon K-edge.